SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                            SCHEDULE 14A INFORMATION


          PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

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     [ ] Soliciting Materials Pursuant to Section 240.14a-11(c) or
         Section 240.14a-12


                       CABOT MICROELECTRONICS CORPORATION
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                (Exact name of Registrant as Specified in Its Charter)

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(CABOT MICROELECTRONICS LOGO)

                       CABOT MICROELECTRONICS CORPORATION
                            870 NORTH COMMONS DRIVE
                             AURORA, ILLINOIS 60504

                    NOTICE OF ANNUAL MEETING OF STOCKHOLDERS
                            To be held March 9, 2004

To our Stockholders:

     We  are  notifying you  that the  Annual Meeting  of Stockholders  of Cabot
Microelectronics Corporation will be held on Tuesday, March 9, 2004 at 8:00 a.m.
local time  at  Cabot Microelectronics  Corporation,  870 North  Commons  Drive,
Aurora, Illinois 60504 for the following purposes:

     1. To elect two directors, each for a term of three years;

     2. To ratify the election of William P. Noglows to the board of directors;

     3. To  ratify the selection of  PricewaterhouseCoopers LLP as the company's
        independent auditors for fiscal year 2004;

     4. To approve our Second Amended  and Restated 2000 Equity Incentive  Plan;
        and

     5. To transact other business properly coming before the meeting.

Each  of these  matters is  described in  further detail  in the  enclosed proxy
statement. We  have  also  enclosed a  copy  of  our 2003  Annual  Report.  Only
stockholders of record at the close of business on January 20, 2004 are entitled
to  vote at the meeting  or any postponements or  adjournments of the meeting. A
complete list of these stockholders will be available at our principal executive
offices prior to the meeting.

     Please use this  opportunity to  take part in  our affairs  by voting  your
shares.  Whether or  not you  plan to  attend the  meeting, please  complete the
enclosed proxy  card and  return it  in  the envelope  provided as  promptly  as
possible or vote electronically through the Internet or by telephone. Your proxy
can be withdrawn by you at any time before it is voted.

                                          By order of the Board of Directors,

                                          /s/ William P. Noglows
                                          William P. Noglows
                                          Chairman of the Board

Aurora, Illinois
January 26, 2004


                               TABLE OF CONTENTS


                                                            
About the Meeting...........................................     1
     What is the purpose of the annual meeting?.............     1
     What are the company's voting recommendations?.........     1
     Who is entitled to vote?...............................     1
     What constitutes a quorum?.............................     1
     How do I vote?.........................................     1
     Can I vote by telephone or through the Internet?.......     2
     Can I revoke my proxy or change my vote after I return
      my proxy card or after I vote electronically or by
      telephone?............................................     2
     What vote is required to approve each matter that comes
      before the meeting?...................................     2
     What happens if additional proposals are presented at
      the meeting?..........................................     2
     Who will bear the costs of soliciting votes for the
      meeting?..............................................     2
Stock Ownership.............................................     3
     Security Ownership of Certain Beneficial Owners and
      Management............................................     3
     Section 16(a) Beneficial Ownership Reporting
      Compliance............................................     5
Election of Directors.......................................     5
Ratification of the Election of William P. Noglows to our
  Board of Directors........................................     7
Ratification of the Selection of Independent Auditors.......     7
Board Structure and Compensation............................     8
     Board of Directors and Board Committees................     8
     Criteria for Nominating Directors......................     9
     Compensation of Directors..............................    10
     Compensation Committee Interlocks And Insider
      Participation.........................................    11
Fees of Independent Auditors and Audit Committee Report.....    11
     Fees Billed by Independent Auditors....................    11
     Report of the Audit Committee..........................    11
Executive Compensation......................................    13
     Summary of Cash and Certain Other Compensation.........    13
     Option Grants..........................................    15
     Option Exercises and Fiscal Year-End Values............    16
     Executive Officer Deposit Share Plan...................    16
     Employment, Termination of Employment, and Change in
      Control Agreements....................................    16
     Standard Employee Benefits.............................    18
Report of the Compensation Committee on Executive
  Compensation..............................................    18
Approval of Second Amended and Restated Cabot
  Microelectronics Corporation 2000
  Equity Incentive Plan.....................................    22
     Existing Plan Information..............................    22
     Existing Equity Compensation Plan Information..........    23
     Amended and Restated 2000 Equity Incentive Plan
      Benefits..............................................    23
     Description of the Second Amended and Restated 2000
      Equity Incentive Plan.................................    24
Certain Relationships and Related Transactions..............    29
Performance Graph...........................................    30
2005 Annual Meeting of Stockholders.........................    31
"Householding" of Proxy Materials...........................    31
Voting Through the Internet or by Telephone.................    31



                       CABOT MICROELECTRONICS CORPORATION
                            870 North Commons Drive
                             Aurora, Illinois 60504
                       ---------------------------------
                                PROXY STATEMENT
                       ---------------------------------

     The  Board of Directors of Cabot Microelectronics Corporation is asking for
your proxy for  use at  the annual  meeting of our  stockholders to  be held  on
Tuesday,  March  9,  2004 at  8:00  a.m.  local time  at  Cabot Microelectronics
Corporation, 870  North  Commons  Drive,  Aurora,  Illinois  60504  and  at  any
postponements  or adjournments  of the  meeting. We  are initially  mailing this
proxy statement and the enclosed proxy  to our stockholders on or about  January
26, 2004.

                               ABOUT THE MEETING

What is the purpose of the annual meeting?

     At  our annual meeting, stockholders will  act upon the matters outlined in
the accompanying notice of meeting, including the election of two directors, the
ratification of the election  of William P. Noglows  to the board of  directors,
the  ratification of the selection of  our independent auditors and the approval
of our Second Amended and Restated 2000 Equity Incentive Plan. In addition,  our
management will report on our performance during the fiscal year ended September
30, 2003 and respond to questions from stockholders.

What are the company's voting recommendations?

     Our  board  of directors  recommends that  you vote  your shares  "FOR" the
election of each  of the  nominees named  below under  "ELECTION OF  DIRECTORS",
"FOR"  the ratification of  the election of  William P. Noglows  to the board of
directors, "FOR" the ratification of  the selection of our independent  auditors
and  "FOR" the approval of our Second Amended and Restated 2000 Equity Incentive
Plan.

Who is entitled to vote?

     Only stockholders of record  at the close of  business on the record  date,
January  20, 2004, are entitled  to receive notice of  the annual meeting and to
vote the shares of common stock that they  held on that date at the meeting,  or
any  postponements or  adjournments of  the meeting.  Each outstanding  share of
common stock entitles its holder to  cast one vote, without cumulation, on  each
matter to be voted on.

What constitutes a quorum?

     If  a majority of the shares outstanding  on the record date are present at
the annual meeting, either in person or by  proxy, we will have a quorum at  the
meeting  permitting the  conduct of  business at the  meeting. As  of the record
date, we had  approximately 24,777,886  shares of common  stock outstanding  and
entitled  to vote. Any shares represented by  proxies that are marked to abstain
from voting on a proposal will be counted as present for purposes of determining
whether we have a quorum. If a broker, bank, custodian, nominee or other  record
holder  of  our  common  stock  indicates  on a  proxy  that  it  does  not have
discretionary authority  to vote  certain  shares on  a particular  matter,  the
shares  held by that record holder (referred to as "broker non-votes") will also
be counted as present in determining whether we have a quorum.

How do I vote?

     You may vote in person at the annual meeting or you may vote by proxy.  You
may  vote by proxy by signing, dating and  mailing the enclosed proxy card or if
you are a record holder of our common stock (that is, if you hold your stock  in
your  own name in the  company's stock records maintained  by our stock transfer

                                       -1-


agent, Equiserve Trust Company, N.A.,  P.O. Box 43010, Providence, Rhode  Island
02940-3010),  by telephone or  through the Internet.  If you vote  by proxy, the
individuals named on the proxy  card as proxy holders  will vote your shares  in
the  manner  you  indicate.  If  you sign  and  return  the  proxy  card without
indicating your instructions, your shares will be voted "FOR":

- the election of the two nominees  for director named below under "ELECTION  OF
  DIRECTORS;"

- the  ratification  of the  election  of William  P.  Noglows to  the  board of
  directors;

- the ratification of the selection of our independent auditors; and

- the approval of our Second Amended and Restated 2000 Equity Incentive Plan.

Can I vote by telephone or through the Internet?

     If you are a record holder of  our common stock, you may vote by  telephone
or  through the Internet by following  the instructions included with your proxy
card.

Can I revoke my proxy or change my vote after I return my proxy card or after I
vote electronically or by telephone?

     Yes. Even after you have submitted your proxy, you may revoke your proxy or
change your vote at any time before the proxy is voted at the annual meeting  by
delivering  to the Secretary of our company  a written notice of revocation or a
properly signed proxy bearing a later  date, or by attending the annual  meeting
and  voting in person. (Attendance at the meeting will not cause your previously
granted proxy to  be revoked unless  you specifically so  request.) To revoke  a
proxy  previously submitted electronically through the Internet or by telephone,
you may simply vote again at a  later date, using the same procedures, in  which
case the later submitted vote will be recorded and the earlier vote revoked.

What vote is required to approve each matter that comes before the meeting?

     Director  nominees must receive the affirmative  vote of a plurality of the
votes cast at the meeting by stockholders entitled to vote thereon, meaning that
the two  nominees  for  director  with  the most  votes  will  be  elected.  The
ratification  of the election of  William P. Noglows to  the board of directors,
the ratification of the selection of  our independent auditors and the  approval
of  our  Second Amended  and  Restated 2000  Equity  Incentive Plan  require the
affirmative vote of a majority of the votes cast at the meeting in person or  by
proxy by stockholders entitled to vote thereon. Abstentions and broker non-votes
will not be counted for purposes of determining whether an item has received the
requisite number of votes for approval.

What happens if additional proposals are presented at the meeting?

     Other  than the matters described in this proxy statement, we do not expect
any additional matters to be presented for a vote at the annual meeting. If  you
vote  by  proxy,  your proxy  grants  the  persons named  as  proxy  holders the
discretion to vote your shares on any additional matters properly presented  for
a vote at the meeting.

Who will bear the costs of soliciting votes for the meeting?

     Certain  directors,  officers  and  employees,  who  will  not  receive any
additional compensation for  such activities,  may solicit  proxies by  personal
interview,  mail, telephone or electronic  communication. We will also reimburse
brokerage houses  and  other  custodians, nominees  and  fiduciaries  for  their
reasonable   out-of-pocket  expenses  for   forwarding  proxy  and  solicitation
materials to  our  stockholders. In  addition  to  the mailing  of  these  proxy
materials, the company has hired the firm of D. F. King & Co., Inc. to assist in
the  solicitation of proxies  at an estimated cost  of approximately $7,500. The
company shall bear all costs of solicitation.

                                       -2-


                                STOCK OWNERSHIP

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

     The following table sets forth certain information regarding the beneficial
ownership of our common stock as of January 20, 2004 (except as indicated below)
by:

        - all  persons  known  by us  to  own  beneficially 5%  or  more  of our
          outstanding common stock;

        - each of our directors;

        - each of the named executive officers in the Summary Compensation Table
          included in this Proxy Statement; and

        - all of our directors and executive officers as a group.

     Unless otherwise indicated, each stockholder  listed below has sole  voting
and  investment power  with respect to  the shares of  common stock beneficially
owned by such stockholder.

                             STOCK OWNERSHIP TABLE



                                                              NUMBER OF SHARES
                                                                BENEFICIALLY         APPROXIMATE
NAME AND ADDRESS                                                  OWNED(1)       PERCENT OF CLASS(1)
----------------                                              ----------------   -------------------
                                                                           

CERTAIN BENEFICIAL OWNERS:
Citigroup, Inc..............................................     3,418,469(2)           13.8%
  388 Greenwich Street
  New York, New York 10013
Wasatch Advisors, Inc.......................................     2,734,212(3)           11.0%
  150 Social Hall Avenue
  Salt Lake City, Utah 84111
FMR Corp....................................................     2,670,877(4)           10.8%
  82 Devonshire Street
  Boston, Massachusetts 02109
T. Rowe Price Associates, Inc...............................     2,007,371(5)            8.1%
  100 E. Pratt Street
  Baltimore, Maryland 21202

DIRECTORS AND EXECUTIVE OFFICERS:
Matthew Neville.............................................       171,228(6)(8)           *
William P. Noglows..........................................        16,153(7)(8)           *
Juan Enriquez-Cabot.........................................        46,561(8)(9)           *
John P. Frazee, Jr..........................................        34,037(8)              *
H. Laurance Fuller..........................................        14,776(8)              *
J. Joseph King..............................................        12,737(8)              *
Ronald L. Skates............................................        34,366(8)              *
Steven V. Wilkinson.........................................        34,580(8)              *
Daniel J. Pike..............................................        73,143(8)              *
H. Carol Bernstein..........................................        59,072(8)              *
Stephen R. Smith............................................        30,000(8)              *
J. Michael Jenkins..........................................        48,541(8)              *

All directors and executive officers as a group (17
  persons)..................................................       711,129(10)           2.9%


---------------

  *  = less than 1%

 (1) "Beneficial  ownership"  generally  means  any  person  who,  directly   or
     indirectly,  has or  shares voting  or investment  power with  respect to a
     security or has  the right  to acquire such  power within  60 days.  Shares

                                       -3-


     of  common stock subject to options,  warrants or rights that are currently
     exercisable or exercisable within  60 days of January  20, 2004 are  deemed
     outstanding  for computing the  ownership percentage of  the person holding
     such options,  warrants  or rights,  but  are not  deemed  outstanding  for
     computing  the ownership  percentage of any  other person.  The amounts and
     percentages  are  based  upon  24,777,886   shares  of  our  common   stock
     outstanding as of January 20, 2004.

 (2) Of the shares reported as beneficially owned, Citigroup, Inc. exercises (a)
     sole power to vote 1,395,345 shares, (b) shared power to vote 0 shares, (c)
     sole  investment power over  0 shares and (d)  shared investment power over
     3,418,469 shares.  This information  is based  on information  reported  in
     Schedule 13F Holdings Report filed by Citigroup, Inc. on November 14, 2003.
     Based  solely on  information reported in  Amendment No. 2  to Schedule 13G
     filed by  Citigroup, Inc.  on  February 7,  2003,  the shares  reported  as
     beneficially owned by Citigroup, Inc. are also partially beneficially owned
     by  Citigroup, Inc.'s wholly-owned subsidiaries Salomon Smith Barney, Inc.,
     Salomon Brothers Holding Company Inc., Smith Barney Fund Management LLC and
     Salomon Smith Barney Holdings Inc.

 (3) Of the  shares  reported  as beneficially  owned,  Wasatch  Advisors,  Inc.
     exercises (a) sole power to vote 2,734,212 shares, (b) shared power to vote
     0  shares, (c) sole  investment power over 2,734,212  shares and (d) shared
     investment power over 0 shares. The number of shares indicated is based  on
     information  reported  in Schedule  13F  Holdings Report  filed  by Wasatch
     Advisors, Inc. on November 17, 2003.

 (4) Of the  shares  reported  as  beneficially  owned,  Fidelity  Management  &
     Research  Company ("Fidelity"), a wholly-owned  subsidiary of FMR Corp., is
     the beneficial  owner  of  2,431,577  shares  as  a  result  of  acting  as
     investment  adviser to various funds. Edward C. Johnson 3d (Chairman of FMR
     Corp.) and FMR Corp. ("FMR")  each has the power  to dispose of the  shares
     beneficially owned by Fidelity, but neither has the power to vote or direct
     the  voting of those shares. The power to  vote or direct the voting of the
     shares resides  with the  Board of  Trustees of  the funds.  Of the  shares
     reported   as  beneficially   owned,  Fidelity   Management  Trust  Company
     ("Fidelity  Management"),  a  wholly-owned   subsidiary  of  FMR,  is   the
     beneficial owner of 129,500 shares as a result of its serving as investment
     manager  of  the  institutional accounts.  Edward  C. Johnson  3d  and FMR,
     through its control of Fidelity Management, each has the dispositive  power
     and  the power to vote or  to direct the voting of  the shares owned by the
     institutional accounts. Of the shares  reported as beneficially owned,  FMR
     beneficially   owns   81,800  shares   through  Strategic   Advisers,  Inc.
     ("Strategic Advisers"),  a wholly-owned  subsidiary  of FMR  that  provides
     investment  advisory services to individuals. Edward C. Johnson 3d has sole
     voting and dispositive power over 28,000 and shared voting and  dispositive
     power  over  0  shares. This  information  is based  solely  on information
     reported in a Schedule  13G filed by  FMR Corp., Edward  C. Johnson 3d  and
     Abigail P. Johnson on December 10, 2003.

 (5) Of  the shares  reported as beneficially  owned, T.  Rowe Price Associates,
     Inc. exercises (a) sole power to  vote 350,446 shares, (b) shared power  to
     vote  0 shares,  (c) sole  investment power  over 2,007,371  shares and (d)
     shared investment power over  0 shares. The number  of shares indicated  is
     based  on information reported in Schedule  13F Holdings Report filed by T.
     Rowe Price Associates, Inc. on November 14, 2003.

 (6) Effective November 2, 2003, Mr. Neville  resigned as Chairman of the  Board
     of  Directors, President  and Chief Executive  Officer. At the  time of his
     resignation, Mr. Neville held 26,228 shares.

 (7) Effective November  3,  2003, Mr.  Noglows  was  elected to  our  Board  of
     Directors and became the Chairman, President and Chief Executive Officer.

                                       -4-


 (8) Includes shares  of our  common stock  that such  person has  the right  to
     acquire pursuant to stock options exercisable within 60 days of January 20,
     2004, as follows:



                                                               SHARES ISSUABLE
NAME                                                            UPON EXERCISE
----                                                           ---------------
                                                            
Mr. Neville.................................................       145,000
Mr. Noglows.................................................            --
Mr. Enriquez-Cabot..........................................        30,000
Mr. Frazee..................................................        30,000
Mr. Fuller..................................................        11,250
Mr. King....................................................        11,250
Mr. Skates..................................................        30,000
Mr. Wilkinson...............................................        30,000
Mr. Pike....................................................        65,000
Ms. Bernstein...............................................        58,375
Mr. Smith...................................................        30,000
Mr. Jenkins.................................................        44,375


     Also  includes phantom  shares of our  common stock  that such non-employee
     director has  the right  to  acquire pursuant  to the  Directors'  Deferred
     Compensation Plan as of January 20, 2004, as follows:



NAME                                                           PHANTOM SHARES
----                                                           --------------
                                                            
Mr. Enriquez-Cabot..........................................        1,792
Mr. Frazee..................................................        2,037
Mr. Fuller..................................................        1,526
Mr. King....................................................        1,487
Mr. Skates..................................................        1,806
Mr. Wilkinson...............................................        2,080


 (9) Includes   1,222  shares  of  our  common   stock  directly  owned  by  Mr.
     Enriquez-Cabot's spouse and 588 shares beneficially owned by a child of Mr.
     Enriquez-Cabot. Does  not include  an  aggregate of  60,582 shares  of  our
     common  stock held in trusts for the  benefit of Mr. Enriquez-Cabot and his
     children, as to which Mr. Enriquez Cabot has no voting or investment power.

(10) Includes 608,520  shares  of  our  common  stock  that  our  directors  and
     executive  officers have  the right  to acquire  pursuant to  stock options
     exercisable within 60 days of January  20, 2004, and 10,728 phantom  shares
     of  our  common stock  that our  non-employee directors  have the  right to
     acquire pursuant to the Directors' Deferred Compensation Plan as of January
     20, 2004.

SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

     Section  16(a)  of  the  Securities  Exchange  Act  of  1934  requires  our
directors,  executive officers and holders of more  than 10% of our common stock
to file  with the  Securities and  Exchange Commission  reports regarding  their
ownership  and changes  in ownership  of our common  stock. Based  solely on our
review of the reports furnished to us, we believe that all of our directors  and
executive  officers filed all  Form 4s made  between June 30,  2002 and June 29,
2003 on time or no later than one business day later than required in accordance
with SEC Release  No. 34-47809,  and otherwise  have complied  with all  Section
16(a) filing requirements for fiscal year 2003.

                             ELECTION OF DIRECTORS

     Our board of directors is currently comprised of seven directors. The board
of  directors is divided into three classes: Class I, whose terms will expire at
the upcoming annual meeting of stockholders;  Class II, whose terms will  expire
at  the annual meeting of stockholders to be  held in 2005; and Class III, whose
terms will expire  at the annual  meeting of  stockholders to be  held in  2006.
Messrs. Enriquez-Cabot and Fuller are currently in Class I, Messrs. King, Skates
and  Wilkinson are  currently in  Class II, and  Messrs. Frazee  and Noglows are
currently in Class III.

                                       -5-


     As of November 2, 2003, Mr. Neville, who had been a Class III director  and
who  was Chairman of the Board, resigned as a director. Effective as of November
3, 2003, our board of directors elected Mr. Noglows to succeed Mr. Neville as  a
Class III director and as Chairman of the Board.

     At  each annual meeting of stockholders,  the successors to directors whose
terms will then expire will  be elected to serve from  the time of election  and
qualification until the third annual meeting following election. Our certificate
of incorporation provides that the authorized number of directors may be changed
only  by  resolution of  the board  of  directors. Any  additional directorships
resulting from an increase in the number of directors will be distributed  among
the  three classes so  that, as nearly  as possible, each  class will consist of
one-third of the  total number  of directors. Our  certificate of  incorporation
also  provides that our board  of directors may fill  any vacancy created by the
resignation of a director or the increase of the size of the board of directors.

     The board  of directors  has nominated  and  urges you  to vote  "FOR"  the
election  of the two  nominees named below  for terms of  office ending in 2007.
Proxies will be so voted unless stockholders specify otherwise in their proxies.

     In the event a nominee  is not available to serve  for any reason when  the
election  occurs, it is intended that the proxies will be voted for the election
of the other nominee and may be  voted for any substitute nominee. Our board  of
directors  has no reason to believe that  either nominee will not be a candidate
or, if elected, will be unable or unwilling to serve as a director. In no  event
will  the proxies be  voted for a greater  number of persons  than the number of
nominees named.

OUR BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE "FOR" THE ELECTION TO THE BOARD
OF EACH OF THE NOMINEES NAMED BELOW.

Nominees for election at this meeting for terms expiring in 2007:

     Juan Enriquez-Cabot, 44,  was elected a  director of our  company in  April
2000.  Since  2003, Mr.  Enriquez-Cabot  has served  as  the Chairman  and Chief
Executive Officer of Biotechonomy, a life sciences research and investment firm.
Mr. Enriquez-Cabot also served  as the Director of  the Life Science Project  at
the   Harvard  Business  School  from  2001-2003.  From  1997  until  2001,  Mr.
Enriquez-Cabot was  a  researcher  at  Harvard  University's  David  Rockefeller
Center.  From 1996 to 1997,  he was a senior  researcher at the Harvard Business
School and a fellow at Harvard University's Center for International Affairs. He
received both his bachelor and MBA degrees from Harvard University.

     H. Laurance Fuller, 65, was elected a director of our company in June 2002.
He is a director of Abbott Laboratories and of Motorola, Inc. Mr. Fuller retired
from the position  of Co-Chairman of  BP Amoco, p.l.c.,  a global petroleum  and
petrochemicals  company, in 2000  after serving as  Chairman and Chief Executive
Officer of Amoco  Corporation since 1991  and President since  1983. Mr.  Fuller
received his B.S. in chemical engineering from Cornell University.

Directors whose terms continue until 2005:

     J.  Joseph King,  59, was  elected a director  of our  company in September
2002. Since 2001, he has served as Vice Chairman and Chief Executive Officer  of
Molex,  Inc. Prior  to 2001,  Mr. King served  as President  and Chief Operating
Officer of Molex and held various  other executive positions at Molex. Mr.  King
received  his master of engineering science  degree from the National University
of Ireland in  Cork and  his master of  industrial engineering  degree from  the
National University of Ireland in Galway.

     Ronald  L. Skates, 62, was elected a director of our company in April 2000.
He has been a private investor since 1999. From 1989 to 1999, Mr. Skates  served
as  President and  Chief Executive  Officer and  as a  director of  Data General
Corporation, a computer systems company. Mr. Skates is also a director of  State
Street  Corporation, Courier  Corporation and Raytheon  Corporation. He received
both his bachelor and MBA degrees from Harvard University.

                                       -6-


     Steven  V. Wilkinson, 62,  was elected a  director of our  company in April
2000. He has been retired since 1998. Prior to retirement, he worked for  Arthur
Andersen  LLP,  where he  became  a partner  in 1974.  Mr.  Wilkinson is  also a
director of Entergy Corporation. Mr. Wilkinson received his BA in economics from
DePauw University and his MBA from the University of Chicago.

Directors whose terms continue until 2006:

     John P. Frazee, Jr.,  59, was elected  a director of  our company in  April
2000. He has been a private investor since 2001. From 1999 until 2001, he served
as  Chairman and Chief Executive Officer of  Vast Solutions, Inc., a provider of
wireless data products and  services. From 1999 to  2000, he served as  Chairman
and Chief Executive Officer of Paging Network, Inc. From 1997 to 1999, he served
as  Chairman, President and Chief Executive Officer of Paging Network. From 1993
until 1997, Mr. Frazee managed investments  as a private investor. During  1993,
he  was President  and Chief Operating  Officer of Sprint  Corporation. Prior to
that, he was  Chairman and  Chief Executive  Officer of  Centel Corporation.  In
addition  to serving on  our board, Mr. Frazee  also serves on  the board of EMS
Technologies, Inc.  Mr.  Frazee  received his  bachelor's  degree  in  political
science from Randolph-Macon College.

     William  P. Noglows,  45, has served  as our Chairman,  President and Chief
Executive Officer since November  3, 2003. From 1984  through 2003, Mr.  Noglows
served  in  various management  positions at  Cabot Corporation,  culminating in
serving as  an executive  vice president  and general  manager. While  at  Cabot
Corporation,  he  was  one  of  the primary  founders  of  our  company  and was
responsible  for  identifying  and  encouraging  the  development  of  the   CMP
application,  which  is the  core  technology of  our  company. Mr.  Noglows had
previously served as a director of  our company from December, 1999 until  April
2002.  Mr. Noglows received his degree  in Chemical Engineering from the Georgia
Institute of Technology.

               RATIFICATION OF THE ELECTION OF WILLIAM P. NOGLOWS
                           TO OUR BOARD OF DIRECTORS

     As of November 2, 2003, Mr. Neville, who had been a Class III director  and
who  was Chairman of the Board, resigned as a director. Effective as of November
3, 2003, as permitted by our by-laws and charter, our board of directors elected
Mr. Noglows to succeed Mr.  Neville as a Class III  director and as Chairman  of
the Board.

     Stockholder  ratification of  the election of  Mr. Noglows to  our board of
directors or other elections  or appointments to our  board of directors is  not
required  by our by-laws or  otherwise. Our board is  submitting the election of
Mr. Noglows to our board of directors to our stockholders for ratification as  a
matter  of good corporate practice as Mr. Noglows has become our Chief Executive
Officer and Chairman of the Board of Directors.  We do not intend to and in  the
future we will not necessarily ratify elections or appointments made pursuant to
our  bylaws to our  board of directors.  If our stockholders  fail to ratify the
election, our board of directors intends  to reconsider the matter. Even if  the
election  is ratified, our board of directors, in its discretion and pursuant to
our bylaws and  charter, may  appoint a  different chairman  at any  time if  it
determines  that such a change would be in the best interests of our company and
our stockholders.

OUR BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE "FOR" THE RATIFICATION OF THE
ELECTION OF MR. NOGLOWS TO OUR BOARD OF DIRECTORS.

             RATIFICATION OF THE SELECTION OF INDEPENDENT AUDITORS

     PricewaterhouseCoopers LLP audited our financial statements for fiscal year
2003, and has been selected by the audit committee of our board of directors  to
audit  our  financial  statements  for fiscal  year  2004.  A  representative of
PricewaterhouseCoopers LLP is expected to attend the annual meeting, where he or
she will have  the opportunity  to make  a statement,  if desired,  and will  be
available to respond to appropriate questions.

     Stockholder  ratification of the selection of PricewaterhouseCoopers LLP as
our independent auditors is not required  by our by-laws or otherwise.  However,
our    board   is    submitting   the    selection   of   PricewaterhouseCoopers
                                       -7-


LLP to our stockholders for ratification as a matter of good corporate practice.
If our  stockholders fail  to ratify  the selection,  our audit  committee  will
review  its future selection of auditors. Even if the selection is ratified, the
audit committee  in  its discretion  may  direct the  appointment  of  different
independent  auditors at any time  during the year if  it determines that such a
change would be in the best interests of our company and our stockholders.

     For   information   regarding    audit   and   other    fees   billed    by
PricewaterhouseCoopers  LLP for services rendered in fiscal year 2003, see "FEES
OF INDEPENDENT AUDITORS AND AUDIT COMMITTEE REPORT -- Fees Billed by Independent
Auditors," below.

OUR BOARD OF DIRECTORS  RECOMMENDS THAT YOU VOTE  "FOR" THE RATIFICATION OF  THE
SELECTION OF OUR INDEPENDENT AUDITORS.

                        BOARD STRUCTURE AND COMPENSATION

BOARD OF DIRECTORS AND BOARD COMMITTEES

     Our  board  of  directors  has  a  standing  audit  committee,  a  standing
compensation committee  and  a  standing  nominating  and  corporate  governance
committee   to  assist  the   board  of  directors  in   the  discharge  of  its
responsibilities. Our board of directors has adopted the Cabot  Microelectronics
Corporation  Corporate Governance Guidelines, which are available on our website
at www.cabotcmp.com along  with other  corporate governance  materials, such  as
board  of directors committee charters and  our Code of Business Conduct. During
fiscal year 2003, the  board of directors  held five meetings  and did not  take
action  by written consent. Each of our directors attended our annual meeting of
stockholders in fiscal years 2002 and 2003 and at least 75% of all the  meetings
of  the board and those  committees on which he  served during fiscal year 2003.
Since fiscal year end, the board of directors has met three times and has  taken
action by written consent twice. Third parties may communicate with our board of
directors through the Chairman of the Board, c/o the Secretary of our company at
our offices at 870 North Commons Drive, Aurora, Illinois 60504.

     INDEPENDENT  DIRECTORS.  The board of  directors has determined that six of
our seven directors,  Messrs. Enriquez-Cabot, Frazee,  Fuller, King, Skates  and
Wilkinson,  are "independent" directors as defined  in Rule 4200 of the National
Association  of  Securities  Dealers'  marketplace  rules  and  as  defined   in
applicable  rules by the SEC. Our independent directors hold regularly scheduled
meetings in executive session, at which only independent directors are  present.
The  Chairman of  the nominating  and corporate  governance committee  serves as
chairman of the meetings of the independent directors in executive session,  and
performs  other responsibilities such as working  with the Chairman of the board
of directors to plan and set the agenda for meetings of the board of  directors.
Third  parties  may  communicate  with  our  independent  directors  through the
Chairman of the nominating and corporate governance committee, c/o the Secretary
of our  company at  our offices  at 870  North Commons  Drive, Aurora,  Illinois
60504.  During  fiscal year  2003, our  independent directors  have met  in such
executive sessions six times. Since  fiscal year end, our independent  directors
have met in such executive sessions nine times.

     AUDIT  COMMITTEE.  The functions of  the audit committee include selecting,
appointing, compensating, retaining and  overseeing our auditors, deciding  upon
and  approving  in advance  the  scope of  audit  and non-audit  assignments and
related fees, reviewing  accounting principles  we use  in financial  reporting,
internal auditing procedures, and reviewing the adequacy of our internal control
procedures.  The  members of  the  audit committee  are  Messrs. Enriquez-Cabot,
Frazee, King and Wilkinson (Chairman), each of whom:

     - is an  "independent"  director as  defined  in Rule  4200(a)(15)  of  the
       National Association of Securities Dealers' marketplace rules;

     - meets  the  criteria for  independence  as required  by  applicable rules
       adopted by the Securities and Exchange Commission (SEC);

     - has not participated in  the preparation of  our financial statements  or
       the  financial statements of any of  our current subsidiaries at any time
       during the past three years; and

     - is able to read and understand fundamental financial statements.
                                       -8-


     Our board of directors has determined that the audit committee has at least
one member who qualifies as an  Audit Committee Financial Expert, as defined  by
relevant  SEC  rules, and  has  designated Mr.  Wilkinson,  the Chairman  of the
committee, as such Audit Committee  Financial Expert. As previously stated,  Mr.
Wilkinson  is  an independent  director. The  audit  committee operates  under a
written charter, a current copy of which is attached to this proxy statement  as
Appendix  A  and is  available  on our  website  at www.cabotcmp.com.  The audit
committee has established procedures for  the receipt, retention, and  treatment
of  complaints received  regarding accounting,  internal accounting  controls or
auditing matters, which are also available on our website www.cabotcmp.com.  The
audit  committee met four times  during fiscal year 2003  and has met once since
fiscal year end  with respect to  the audit  of our fiscal  year 2003  financial
statements  and  related  matters.  In  fulfillment  of  the  audit  committee's
responsibilities for  fiscal  year  2003, Mr.  Wilkinson,  the  audit  committee
Chairman,  reviewed our  Annual Report  on Form 10-K  for the  fiscal year ended
September 30, 2003  (as did  the other  members of  the committee  and board  of
directors),  and our Quarterly  Reports on Form  10-Q before we  filed them, and
reviewed quarterly earnings announcements before we released them.

     COMPENSATION COMMITTEE.    The  functions  of  the  compensation  committee
include reviewing and approving the compensation and benefits for our employees,
evaluating  and deciding upon  the compensation of  our chief executive officer,
evaluating and deciding upon the  compensation of our other executive  officers,
which   is  done  following  consultation  with  our  chief  executive  officer,
administering our employee benefit plans, authorizing and ratifying stock option
grants and other incentive arrangements, and authorizing employment and  related
agreements.  Our  chief  executive  officer is  neither  present  for  voting or
deliberation on,  nor votes  upon  decisions relating  to his  compensation.  In
addition,  our chief executive  officer does not vote  upon decisions related to
the compensation of our other executive  officers. During fiscal year 2003,  the
compensation  committee was  comprised of  Messrs. Frazee,  Fuller, King, Skates
(Chairman) and Wilkinson, each of whom  is an "independent" director as  defined
in   Rule  4200(a)(15)  of  the  National  Association  of  Securities  Dealers'
marketplace rules and  as defined in  applicable rules adopted  by the SEC.  The
compensation   committee  operates  under  a   written  charter  that  addresses
compensation matters, a  current copy of  which is available  on our website  at
www.cabotcmp.com.  The compensation committee met three times and took action by
written consent twice during  fiscal year 2003.  The compensation committee  has
met  once and has  taken action by  written consent four  times since the fiscal
year end with  respect to 2003  annual bonuses, salary  increases, stock  option
grants and other matters.

     NOMINATING  AND  CORPORATE  GOVERNANCE  COMMITTEE.  The  functions  of  the
nominating and corporate governance committee include reviewing and recommending
a slate of nominees for the  election of directors, recommending changes in  the
number,   classification  and  term  of   directors,  reviewing  nominations  by
stockholders with regard to the  nomination process, reviewing and  recommending
compensation  and  other matters  for our  directors,  and attending  to general
corporate governance  matters.  The  members of  the  nominating  and  corporate
governance  committee are Messrs. Enriquez-Cabot,  Frazee (Chairman), Fuller and
Skates, each of whom is an "independent" director as defined in Rule 4200(a)(15)
of the  National Association  of Securities  Dealers' marketplace  rules and  as
defined  in applicable  rules adopted by  the SEC. The  nominating and corporate
governance  committee  operates  under  a  formal  charter  that  addresses  the
nominations  process  and such  related  matters as  may  be required  under the
federal securities laws and Nasdaq listing requirements, a current copy of which
is available on our  website at www.cabotcmp.com.  The nominating and  corporate
governance committee met four times during fiscal year 2003, has taken action by
written consent once and has met twice since fiscal year end. The nominating and
corporate  governance committee acted unanimously to recommend the nomination of
the Class I director nominees to the board of directors, subject to  stockholder
approval, as discussed in "ELECTION OF DIRECTORS," above.

CRITERIA FOR NOMINATING DIRECTORS

     The  nominating and corporate governance  committee considers candidates to
fill new directorships  created by expansion  and vacancies that  may occur  and
makes recommendations to the board of directors with respect to such candidates.
The  nominating and  corporate governance  committee considers  suggestions from
many sources  regarding  possible  candidates for  director  and  will  consider
nominees recommended by stockholders. Any such stockholder nominations, together
with appropriate biographical information, should

                                       -9-


be  submitted  to  the  Chairman  of  the  nominating  and  corporate governance
committee, c/o the Secretary of our company at our offices at 870 North  Commons
Drive,  Aurora,  Illinois 60504.  To be  included in  the proxy  statement, such
nomination must be received by the Secretary  of our company not later than  the
120th  day prior to  the first anniversary  of the date  of the preceding year's
proxy statement for such nomination.

     In fiscal year 2003, the  company did not pay a  fee to any third party  to
identify  or evaluate potential director nominees; however, our directors play a
critical role in guiding our  strategic direction and overseeing the  management
of  the company and accordingly, in the future we may pay a fee to a third party
to identify or evaluate potential director nominees if the need arises.

     Board candidates are selected based  upon various criteria including  their
character,  business  experience  and  acumen.  Some  of  the  factors  that are
considered  in  evaluating  candidates  for  the  board  of  directors   include
experience  in  areas  such as  technology,  manufacturing,  marketing, finance,
strategy, international  business,  and  academia, as  well  as  geographic  and
cultural  diversity.  Board members  are expected  to  prepare for,  attend, and
participate in all board of directors and applicable committee meetings, and our
annual  meetings  of  stockholders.  The  nominating  and  corporate  governance
committee  considers  a  director's past  attendance  record,  participation and
contribution to the board of directors  in considering whether to recommend  the
reelection of such director.

COMPENSATION OF DIRECTORS

     A director who is also our employee receives no additional compensation for
his services as a director. Each of our directors who is not an employee of ours
currently receives the following:

     - upon  his  original appointment  or election  as  a director,  options to
       purchase 15,000 shares of our common  stock which vest over a three  year
       period;

     - on  an annual basis, options to purchase 7,500 shares of our common stock
       which vest over a four year period;

     - a $20,000 annual fee;

     - a $1,000 fee for attendance at each meeting of our board of directors  or
       a committee of the board; and

     - reimbursement  of  travel  and  other  out-of-pocket  costs  incurred  in
       attending meetings.

     Additionally, the audit committee  chairman receives an additional  $10,000
annual fee for serving as the audit committee chairman.

     Under our Directors' Cash Compensation Umbrella Program, which only applies
to  non-employee directors, each non-employee director may choose to receive his
compensation either in cash, in fully vested restricted stock under our  Amended
and  Restated Cabot Microelectronics Corporation  2000 Equity Incentive Plan (as
of the date the fees are earned, the fees would be converted into the equivalent
number of fully vested restricted shares, which would be beneficially owned  and
reported  on Form 4  filings), or as deferred  compensation under our Directors'
Deferred Compensation Plan. At present,  each of our non-employee directors  has
elected  to  defer  his  compensation to  future  periods  under  the Directors'
Deferred Compensation  Plan, which  became effective  in March  2001. Under  the
plan,  as amended in June 2003, deferred amounts are payable only in the form of
our common shares. A participating director is required to elect a date on which
deferred compensation will begin to be distributed, which date generally must be
at least two years after the end of the year deferrals are made. As of the  date
the  shares are  earned, the fees  are converted  into the right  to acquire the
equivalent number of shares of common stock  at the end of the deferral  period.
These  rights to acquire shares under  the Directors' Deferred Compensation Plan
are reported as  beneficially owned  on Form  4 filings  for each  participating
director.  As of  January 20, 2004,  an aggregate of  approximately $552,832, of
directors' compensation was deferred under the plan.

                                       -10-


COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION

     None of the current or former members of the compensation committee are  or
have been our employees.

            FEES OF INDEPENDENT AUDITORS AND AUDIT COMMITTEE REPORT

FEES BILLED BY INDEPENDENT AUDITORS

     During  fiscal years  2002 and 2003,  the audit  committee pre-approved all
audit and non-audit services provided by our independent auditors. The following
table presents fees  for audit services  rendered by PricewaterhouseCoopers  LLP
for  the audit of the company's annual  financial statements for the fiscal year
ended September 30,  2003, and  September 30, 2002,  and fees  billed for  other
services  rendered by  PricewaterhouseCoopers LLP during  those periods. Certain
amounts for 2002 have been reclassified to conform to the 2003 presentation.



                                                  FISCAL YEAR ENDED        FISCAL YEAR ENDED
FEES                                            SEPTEMBER 30, 2003 ($)   SEPTEMBER 30, 2002 ($)
----                                            ----------------------   ----------------------
                                                                   
Audit Fees(1).................................         521,240                  458,980
Audit-Related Fees(2).........................          50,483                   31,540
Tax Fees(3)...................................         336,526                  309,441
All Other Fees(4).............................               0                        0
                                                       -------                  -------
  Total.......................................         908,249                  799,961


---------------

(1) Audit Fees include  fees for  services that  normally would  be provided  by
    PricewaterhouseCoopers  LLP  in  connection  with  statutory  and regulatory
    filings or engagements. In addition to including fees for services necessary
    to perform an audit  or review in accordance  with GAAP, this category  also
    may   include  services  that   generally  only  PricewaterhouseCoopers  LLP
    reasonably can provide,  such as comfort  letters, statutory audits,  attest
    services,  consents and assistance  with and review  of documents filed with
    the SEC.

(2) Audit Related  Fees  include  assurance  and  related  services  (e.g.,  due
    diligence  services) traditionally  performed by  PricewaterhouseCoopers LLP
    including employee benefit plan audits, due diligence related to mergers and
    acquisitions,  accounting  consultations  and  audits  in  connection   with
    acquisitions,  internal  control  reviews,  attest  services  that  are  not
    required by  statute or  regulation  and consultation  concerning  financial
    accounting and reporting standards.

(3) Tax   Fees  include  all   services  performed  by   professional  staff  in
    PricewaterhouseCoopers LLP's tax division  except those services related  to
    the  audit, including fees for tax compliance, tax planning, and tax advice.
    Tax compliance generally  involves preparation of  original and amended  tax
    returns,  claims for refund and  tax payment-planning services. Tax planning
    and tax advice encompass a  diverse range of services, including  assistance
    with tax audits and appeals, tax advice related to mergers and acquisitions,
    employee  benefit plans  and requests for  rulings or  technical advice from
    taxing authorities.

(4) All Other  Fees  includes  fees related  to  financial  information  systems
    implementation  and design services. Our independent auditors did not render
    any such services to us in fiscal year 2003 or any prior year.

REPORT OF THE AUDIT COMMITTEE

     The following report of the audit committee does not constitute  soliciting
material  and should not be  deemed filed or incorporated  by reference into any
other of our filings under the Securities Act of 1933 or the Securities Exchange
Act of 1934,  except to the  extent we specifically  incorporate this report  by
reference therein.

     The  audit committee of the board of directors is responsible for providing
independent, objective  oversight  of the  company's  accounting and  system  of
internal controls, the quality and integrity of the company's financial reports,
and the independence and the selection, appointment, retention, compensation and
oversight  of the performance  of the company's  independent auditors. The audit
committee is comprised of

                                       -11-


independent directors and operates  under a written charter,  a current copy  of
which is attached to this proxy statement as Appendix A and is also available on
our website at www.cabotcmp.com.

     Management  is  responsible for  the  company's internal  controls  and the
financial reporting  process.  The  independent  auditors  are  responsible  for
performing  an  independent  audit  of  the  company's  financial  statements in
accordance with generally accepted  auditing standards and  issuing a report  on
those  financial  statements. The  audit committee  monitors and  oversees these
processes.

     In this context,  the audit  committee reviewed and  discussed the  audited
financial  statements  for  fiscal  year  2003  with  management  and  with  the
independent auditors. Specifically, the audit  committee has discussed with  the
independent  auditors  the  matters required  to  be discussed  by  Statement on
Auditing Standards No. 61 (Communications with Audit Committees), which include,
among other things:

     - methods used to account for any significant and unusual transactions;

     - the effect of  any significant  accounting policies  in controversial  or
       emerging  areas for  which there is  a lack of  authoritative guidance or
       consensus;

     - the process used by management in formulating any particularly  sensitive
       accounting   estimates  and  the  basis  for  the  auditors'  conclusions
       regarding the reasonableness of those estimates; and

     - any disagreements  with management  over  the application  of  accounting
       principles,  the  basis for  management's  accounting estimates,  and the
       disclosures in the financial statements.

     The audit  committee believes  strongly in  the principles  underlying  the
requirement  that  independent auditors  maintain  their independence  in strict
compliance with applicable independence rules. The audit committee has  received
the written disclosures and the letter from the independent auditors required by
Independence Standards Board Standard No. 1 (Independence Discussions With Audit
Committees)  and has  discussed with the  independent auditors the  issue of the
independent auditors' independence from the company and management. In addition,
in accordance with the Securities and Exchange Commission's auditor independence
requirements,  the  audit  committee  has  considered  whether  the  independent
auditors'  provision of  non-audit services  to the  company is  compatible with
maintaining the independence of the auditors and has concluded that it is.

     Based on its  review of the  audited financial statements  and the  various
discussions  noted  above,  the  audit committee  recommended  to  the  board of
directors that the  audited financial  statements be included  in the  company's
Annual Report on Form 10-K for the fiscal year ended September 30, 2003.

     Respectfully submitted by the audit committee,

                              Juan Enriquez-Cabot
                              John P. Frazee, Jr.
                                 J. Joseph King
                         Steven V. Wilkinson, Chairman

                                       -12-


                             EXECUTIVE COMPENSATION

SUMMARY OF CASH AND CERTAIN OTHER COMPENSATION

     The  following table  sets forth  certain compensation  information for the
Chief Executive Officer and our four other executive officers who were the  most
highly  compensated for the fiscal year  ended September 30, 2003 (together, the
"named executive  officers"). All  of  the information  in this  table  reflects
compensation earned by the named executive officers for services rendered to us.

                           SUMMARY COMPENSATION TABLE



-------------------------------------------------------------------------------------------------------------------------
                                                     ANNUAL                         LONG-TERM
                                                  COMPENSATION                 COMPENSATION AWARDS
                                         -------------------------------   ----------------------------
                                                                 OTHER
                                                                ANNUAL                       SECURITIES   ALL OTHER
             NAME AND            FISCAL                         COMPEN-    RESTRICTED STOCK  UNDERLYING    COMPEN-
        PRINCIPAL POSITION        YEAR   SALARY($)  BONUS($)   SATION($)     AWARD(S)($)     OPTIONS(#)  SATION($)(4)
-------------------------------------------------------------------------------------------------------------------------
                                                                                           
    Matthew Neville(1)            2003    393,750   300,000          --            --        100,000(3)   35,753
      Former President and        2002    368,750   260,000          --            --        100,000      36,942
      Chief Executive Officer     2001    325,000   310,000          --            --        100,000      36,247
-------------------------------------------------------------------------------------------------------------------------
    William P. Noglows(2)         2003         --        --          --            --             --(3)       --
      President and               2002         --        --          --            --             --(2)       --
      Chief Executive Officer     2001         --        --          --            --             --(2)       --
-------------------------------------------------------------------------------------------------------------------------
    Daniel J. Pike                2003    247,875   150,000          --            --         54,000(3)   23,832
      Vice President              2002    236,250   107,000          --            --         50,000      23,989
      of Operations               2001    211,250   120,000          --            --         54,000      22,151
-------------------------------------------------------------------------------------------------------------------------
    H. Carol Bernstein            2003    227,500   140,000       8,000(6)         --         47,500(3)   24,279
      Vice President, Secretary   2002    217,500    96,000       8,000(6)         --         42,000      22,803
      and General Counsel         2001    207,500   112,000       8,000(6)         --         47,000      19,819
-------------------------------------------------------------------------------------------------------------------------
    Stephen R. Smith              2003    208,625   125,000         670(6)         --         57,000(3)   20,617
      Vice President of           2002    185,640   128,000(5)   58,168(6)         --         27,000      19,118
      Marketing and Sales         2001         --        --          --            --             --          --
-------------------------------------------------------------------------------------------------------------------------
    J. Michael Jenkins            2003    201,750    90,000          --            --         47,500      21,696
      Vice President of           2002    174,057    85,000          --            --         42,000      20,520
      Human Resources             2001    168,625    96,000          --            --         45,000      21,825
-------------------------------------------------------------------------------------------------------------------------


-------------------------

(1) Mr.  Neville resigned from his position as our President and Chief Executive
    Officer, effective as of November 2, 2003.

(2) Mr. Noglows  joined us  as our  new President  and Chief  Executive  Officer
    effective  November 3, 2003. Mr. Noglows had previously served as an outside
    director of our  company from  the time of  our initial  public offering  in
    April  2000 through April 2002, after first having been appointed a director
    in December, 1999.  These amounts do  not include options  to acquire  7,500
    shares  granted to Mr.  Noglows in March  2001 and options  to acquire 7,500
    shares granted to Mr. Noglows in March 2002 as compensation for his  service
    on  our board of directors. Upon his resignation from our board of directors
    in April 2002, any such options, as well as options that he had been granted
    for service as a director in  April 2000, that were unvested, terminated  in
    accordance with their terms.

(3) These  amounts  do  not include  options  granted  to certain  of  our named
    executive officers after the end of  fiscal year 2003. On November 3,  2003,
    as part of Mr. Noglows' employment agreement to join the company, we granted
    him  250,000 options at an exercise price  of $55.37 that expire on November
    3,

                                       -13-


2013. On December 11, 2003, we granted options to certain of our named executive
officers  that have an exercise price of  $48.91 and expire December 11, 2013 in
the amounts set forth in the table below:



                                                                  SECURITIES
                                                                  UNDERLYING
                                                                   OPTIONS
    NAME                                                             (#)
    ----                                                          ----------
                                                               
    Mr. Neville.................................................         0
    Mr. Noglows.................................................         0
    Mr. Pike....................................................    60,000
    Ms. Bernstein...............................................    60,000
    Mr. Smith...................................................    60,000
    Mr. Jenkins.................................................         0


(4) The information  in  the column  headed  "All Other  Compensation"  includes
    matching  contributions  to  our tax-qualified  savings  plans (collectively
    referred  to  as  "401(k)  Plan")  and  accruals  under  our   non-qualified
    supplemental savings plans (collectively referred to as "Supplemental Plan")
    for  fiscal  year 2003  on behalf  of  the named  executive officers  in the
    following amounts:



                                                                    401(k)        SUPPLEMENTAL
    NAME                                                             PLAN             PLAN
    ----                                                          -----------   -----------------
                                                                          
    Mr. Neville.................................................    $17,000          $18,150
    Mr. Noglows.................................................          0                0
    Mr. Pike....................................................     17,454            5,880
    Ms. Bernstein...............................................     18,942            4,880
    Mr. Smith...................................................     16,276            3,920
    Mr. Jenkins.................................................     17,910            3,380


    In fiscal year 2003, we provided  each of our named executive officers  with
    basic  life  insurance  and  accidental  death  and  dismemberment insurance
    coverage that was provided on the same basis to all of our employees.  There
    is  no cash  surrender value  associated with  this insurance  coverage. The
    value paid for this  coverage attributable to  each named executive  officer
    (Mr.  Neville, $603; Mr.  Noglows, $0; Mr. Pike,  $497; Ms. Bernstein, $457;
    Mr. Smith,  $420 and  Mr. Jenkins,  $406) is  also reflected  in the  column
    headed "All Other Compensation" for fiscal 2003.

    In  addition, adjustments were  made to correct  amounts of contributions to
    accounts of certain named executive officers that are reflected in the  "All
    Other  Compensation" amounts  for fiscal  years 2001  and 2002.  None of the
    adjustments were material.

(5) These figures include a sign-on bonus of $30,000 paid to Mr. Smith in fiscal
    year 2002. Mr. Smith's hire date was October 29, 2001.

(6) These figures reflect  transportation allowances paid  to Ms. Bernstein  for
    fiscal  years 2001, 2002 and 2003,  and reimbursement of relocation expenses
    paid to Mr. Smith in fiscal year 2002 and 2003.

                                       -14-


OPTION GRANTS

     The  following table sets  forth the number  of shares of  our common stock
underlying the options granted to the named executive officers during the fiscal
year ended September 30, 2003.

                       OPTION GRANTS IN LAST FISCAL YEAR



-----------------------------------------------------------------------------------------------------------------------
                                                         PERCENT OF
                                        NUMBER          TOTAL OPTIONS                                     GRANT
                                      OF SHARES          GRANTED TO        EXERCISE                        DATE
                                      UNDERLYING        EMPLOYEES IN        PRICE        EXPIRATION      PRESENT
               NAME                OPTIONS GRANTED       FISCAL YEAR     PER SHARE($)       DATE       VALUE($)(1)
-----------------------------------------------------------------------------------------------------------------------
                                                                                               
    Matthew Neville                    100,000(2)           10.9%           $51.37         12/11/12     3,254,541
-----------------------------------------------------------------------------------------------------------------------
    William P. Noglows                      --(3)              --               --               --            --
-----------------------------------------------------------------------------------------------------------------------
    Daniel J. Pike                   54,000(2)(3)            5.9%           $51.37         12/11/12     1,757,452
-----------------------------------------------------------------------------------------------------------------------
    H. Carol Bernstein               47,500(2)(3)            5.2%           $51.37         12/11/12     1,545,907
-----------------------------------------------------------------------------------------------------------------------
    Stephen R. Smith                 57,000(2)(3)            6.2%           $51.37         12/11/12     1,855,089
-----------------------------------------------------------------------------------------------------------------------
    J. Michael Jenkins               47,500(2)(3)            5.2%           $51.37         12/11/12     1,545,907
-----------------------------------------------------------------------------------------------------------------------


-------------------------

(1) These values were estimated using  the Black-Scholes option pricing  formula
    on  the basis of the following assumptions: expected volatility: 76.0%; risk
    free rate of  return: 3.0%;  annualized dividend yield:  0.0%; and  expected
    time until exercise: 5.0 years.

(2) These  options have a term of ten years, expiring December 11, 2012, vesting
    in equal amounts annually over a four-year period, within the first quarter.

(3) This table  does  not  include  options granted  to  certain  of  our  named
    executive  officers after the end of fiscal  year 2003. On November 3, 2003,
    as part of Mr. Noglows' employment agreement to join our company, we granted
    to him 250,000 options that vest  in equal increments upon each  anniversary
    over  four years and have a term of ten years, expiring November 3, 2013, at
    an exercise price of $55.37. For fiscal year 2004, on December 11, 2003,  we
    granted 60,000 options to each Mr. Pike, Ms. Bernstein, and Mr. Smith. These
    options have an exercise price of $48.91, vest in equal increments upon each
    anniversary over four years, and have a term of ten years, expiring December
    11, 2013.

                                       -15-


OPTION EXERCISES AND FISCAL YEAR-END VALUES

     The following table sets  forth information with respect  to the number  of
unexercised  stock options held by the named executive officers on September 30,
2003, and the value of the unexercised in-the-money stock options on that date.

              AGGREGATED OPTION EXERCISES IN LAST FISCAL YEAR AND
                         FISCAL YEAR-END OPTION VALUES



                                                                   NUMBER OF SECURITIES
                                 SHARES                           UNDERLYING UNEXERCISED           VALUE OF UNEXERCISED
                                ACQUIRED                                 OPTIONS                 IN-THE-MONEY OPTIONS AT
                                  UPON            VALUE           AT FISCAL YEAR END (#)          FISCAL YEAR-END ($)(1)
             NAME             EXERCISES (#)    REALIZED ($)    EXERCISABLE    UNEXERCISABLE    EXERCISABLE    UNEXERCISABLE
-------------------------------------------------------------------------------------------------------------------------------
                                                                                                    
    Matthew Neville              15,000           480,815        150,000         225,000        2,818,000        863,250
-------------------------------------------------------------------------------------------------------------------------------
    William P. Noglows(2)        40,000         1,575,544         --              --               --             --
-------------------------------------------------------------------------------------------------------------------------------
    Daniel J. Pike               25,000         1,040,813         51,500         118,500          500,435        448,665
-------------------------------------------------------------------------------------------------------------------------------
    H. Carol Bernstein            5,000            55,720         46,500         102,500          140,965        385,995
-------------------------------------------------------------------------------------------------------------------------------
    Stephen R. Smith             --                --             11,750          72,250           21,863        308,408
-------------------------------------------------------------------------------------------------------------------------------
    J. Michael Jenkins           20,500           378,645         32,500         101,500          356,300        385,995
-------------------------------------------------------------------------------------------------------------------------------


-------------------------
(1) We determined the value of unexercised in-the-money options as of  September
    30,  2003 by taking the difference between  the fair market value of a share
    of our common stock on September 30, 2003 of $55.63 and the option  exercise
    price  of the applicable in-the-money option  grant multiplied by the number
    of shares underlying those options as of that date.

(2) While employed  by  Cabot  Corporation through  August,  2003,  Mr.  Noglows
    exercised  options that had been  granted to him at  the time of our initial
    public offering  for  his  service  as  an  employee  of  Cabot  Corporation
    according to their terms.

EXECUTIVE OFFICER DEPOSIT SHARE PLAN

     Our executive officers are eligible to participate in the Executive Officer
Deposit  Share Plan, which was adopted by  the board of directors in March 2000.
Under this plan, our executive officers are entitled to convert all or a portion
of their bonus compensation  into shares of restricted  stock awarded under  the
2000  Equity  Incentive Plan.  These  shares are  retained  on deposit  with our
company until the third anniversary of  the date of deposit ("deposit  shares"),
and  our company matches the deposit with  a restricted stock grant equal to 50%
of the shares deposited by the participant ("award shares"). If the  participant
is  employed by our company on the third anniversary of the deposit date and the
deposit shares have remained on deposit with our company through such date,  the
restrictions  on the  award shares  will lapse.  Five individuals  are currently
participating in  the deposit  share  plan, and  2,542 shares  (including  award
shares) are currently on deposit under that plan.

EMPLOYMENT, TERMINATION OF EMPLOYMENT, AND CHANGE IN CONTROL AGREEMENTS

     Effective  November  2,  2003,  Mr.  Neville  resigned  from  our  board of
directors and  as  our  Chairman,  President and  Chief  Executive  Officer.  On
November  3, 2003, we  entered into an Employment  and Transition Agreement with
Mr. Neville, our former President and Chief Executive Officer that provided  for
the  continuation of his employment with our  company until November 3, 2005. In
consideration of Mr. Neville continuing to provide advice to the new  leadership
of our company and of the other terms of the agreement, including those relating
to  a non-competition,  confidentiality, and a  general release  from claims, we
agreed to  pay Mr.  Neville a  bonus of  $300,000 for  fiscal year  2003,  which
already  has been paid, and  to continue his annual  base salary of $400,000 for
the  remainder  of  his   employment  with  us.  As   part  of  the   agreement,

                                       -16-


Mr.  Neville's Change  in Control  Severance Protection  Agreement terminated on
November 3, 2003, and subject to its terms, all provisions cease as of  November
3,  2004.  If any  payments become  due  under the  Change in  Control Severance
Protection Agreement, Mr. Neville will not receive any remaining payments  under
the Employment and Transition Agreement.

     On  November  2, 2003,  we entered  into an  employment agreement  with Mr.
Noglows to become our Chairman, President and Chief Executive Officer.  Pursuant
to  this employment agreement, among other terms, we agree to pay Mr. Noglows an
annual base salary of $450,000 and a  cash bonus for fiscal year 2004 that  will
not  be less than $160,000, following the end of fiscal year 2004. Additionally,
we granted Mr. Noglows an option to purchase 250,000 shares of our common  stock
at  an exercise price of $55.63 that  vests in four equal annual installments on
each subsequent anniversary of November 3, 2003, and that expires on November 3,
2013. We  also have  agreed to  pay Mr.  Noglows one  year's base  salary if  we
terminate  his employment  without cause and  to provide  certain relocation and
other reimbursements.

     Mr. Jenkins recently informed us that  he intends to resign his  employment
as Vice President of Human Resources, effective as of February 29, 2004. We have
agreed to pay to Mr. Jenkins, subject to the satisfaction of certain conditions,
the  sum of one-year's  salary of $204,000,  which will be  paid in twelve equal
monthly installments, and a fiscal year 2003 bonus of $90,000, which already has
been paid. Mr. Jenkins also will be eligible to receive reimbursement for  costs
associated with certain relocation and outplacement services.

     Jeremy  K. Jones,  who has  served as  the Vice  President of  New Business
Development, also has recently decided to resign from the company, effective  as
of  January  31, 2004.  We  have agreed  to  pay to  Mr.  Jones, subject  to the
satisfaction of certain conditions,  the sum of  one-year's salary of  $188,200,
which  will be paid in twelve equal monthly installments, and a fiscal year 2003
bonus of $40,000, which already has been  paid. Mr. Jones will also be  eligible
to   receive  reimbursement  for  costs  associated  with  certain  outplacement
services.

     In consideration of the amounts to be  paid to each of Messrs. Jenkins  and
Jones  pursuant  to the  arrangements described  above,  each executive  will be
required to adhere to certain  non-competition and confidentiality terms and  to
provide to us a general release from claims.

     In  addition  to  these  arrangements,  the  company  has  entered  into an
employment agreement with Clifford L. Spiro, our Vice President of Research  and
Development, under which we would be obligated to pay him one year's base salary
if  we terminate  his employment  without cause.  We have  not entered  into any
employment or termination of employment agreements  with any of our other  named
executive officers or other executive officers.

     The  company entered into Change in Control Severance Protection Agreements
("change in  control agreements")  with each  of the  named executive  officers.
Pursuant  to  the terms  of  the Employment  and  Transition Agreement  with Mr.
Neville, Mr. Neville's  change in  control agreement terminated  on November  3,
2003,  and subject to  its terms, all  provisions cease as  of November 3, 2004.
Under the change in control agreements, each executive whose employment with our
company terminates, other  than for  cause, disability, death  or certain  other
specified  reasons, within two years (in the case of Ms. Bernstein, Mr. Jenkins,
Mr. Pike and  Mr. Smith) or  three years (in  the case of  Mr. Noglows) after  a
"change  in control" of our company (as such term is defined in the agreements),
is entitled to a severance benefit.  The severance benefit includes accrued  and
unpaid  salary and  bonuses plus two  times (in  the case of  Ms. Bernstein, Mr.
Jenkins, Mr. Pike and Mr. Smith) or three times (in the case of Mr. Neville  and
Mr.  Noglows) the executive's annual cash  compensation (salary plus bonus). The
severance benefit also includes  health and welfare benefits  for 24 months  (in
the case of Ms. Bernstein, Mr. Jenkins, Mr. Pike and Mr. Smith) or 36 months (in
the  case of Mr. Neville and  Mr. Noglows) following the executive's termination
date. We also  have similar  change in control  severance protection  agreements
providing  for two  times severance benefits  in place with  our other executive
officers.

                                       -17-


     Under the change in control agreements,  all amounts accrued or awarded  to
the  executives  under any  incentive  compensation or  benefit  plan, including
options and restricted stock granted under the 2000 Equity Incentive Plan,  will
immediately vest on each executive's respective termination date.

     The  change in control  agreements provide each  executive a full "gross-up
payment" of all excise  taxes assessed on amounts  received under the change  in
control  agreements, as well as all other taxes  that may become due as a result
of the gross-up payment.

STANDARD EMPLOYEE BENEFITS

     We have adopted  various employee  benefit plans and  arrangements for  the
purpose  of  providing  compensation  and employee  benefits  to  our employees,
including our executive officers. These plans and arrangements include an equity
incentive plan, an employee  stock purchase plan,  a tax-qualified savings  plan
and a non-qualified supplemental savings plan.

         REPORT OF THE COMPENSATION COMMITTEE ON EXECUTIVE COMPENSATION

The  following report  of the compensation  committee and  the performance graph
included elsewhere in this proxy statement do not constitute soliciting material
and should not be deemed  filed or incorporated by  reference into any other  of
our  filings under the Securities Act of  1933 or the Securities Exchange Act of
1934, except  to the  extent  we specifically  incorporate  this report  or  the
performance graph by reference therein.

     GENERAL.  The company's  executive compensation program  is administered by
the compensation committee of the board  of directors, which is composed  solely
of   independent  directors.  The  compensation  committee  is  responsible  for
determining the level of compensation paid to our chairman, president and  chief
executive officer and our other executive officers, and determining awards under
and  administering the  Second Amended and  Restated 2000  Equity Incentive Plan
("2000 Equity Incentive Plan"). The  compensation committee is also  responsible
for  reviewing and establishing all other executive compensation plans which the
company may adopt from time to time.

     During and  for  fiscal year  2003,  the compensation  committee  made  all
decisions  pertaining to the compensation of  our former Chairman, President and
Chief Executive Officer, Mr. Matthew  Neville, our named executive officers  and
our  other  executive officers.  The  compensation committee  also  reviewed and
approved  the  methodology  used  for  compensation  of  our  general   employee
population.  The  compensation committee,  which was  established in  April 2000
concurrent with the completion of our IPO, has made all decisions pertaining  to
the  compensation of  our executive  officers since  its creation.  In November,
2003, the compensation committee,  along with the  independent directors of  our
board  of  directors, and  in consultation  with outside  advisors hired  by the
committee,  made  all  decisions  relating  to  the  Employment  and  Transition
Agreement  with Mr. Neville,  who resigned as our  Chairman, President and Chief
Executive Officer in November, 2003. In addition, the compensation committee, in
consultation with outside advisors  hired by the  committee, made all  decisions
pertaining  to the  employment offer and  agreement and compensation  of our new
Chairman, President and Chief Executive Officer, Mr. William P. Noglows, who was
appointed to these positions in November, 2003.

     COMPENSATION POLICY AND OVERALL OBJECTIVES.  In determining the amount  and
composition  of  executive  compensation,  the committee's  goal  is  to provide
compensation that  will  enable  the  company to  attract  and  retain  talented
executives,  align compensation  with business  objectives and  performance, and
link the interests of the company's executives to the interests of the company's
stockholders.

     The compensation committee believes that  each element of the  compensation
program  should  target  compensation levels  at  rates that  take  into account
current market practices.  Offering market-comparable  pay opportunities  allows
the  company to  maintain a  stable, successful  management team.  The company's
market for compensation comparison purposes is comprised of a group of companies
that develop or use  semiconductor products and processes,  with an emphasis  on
chemical  mechanical planarization products and  processes, as well as companies
that have similar sales volumes, market capitalizations, employment levels,  and
geographic

                                       -18-


presence.  In evaluating  this comparison  group for  compensation purposes, the
compensation committee exercises  its discretion  and makes  its judgment  after
considering all relevant factors.

     The  key elements of the company's  executive compensation program are base
salary, annual  bonuses and  long-term incentives.  Each of  these is  addressed
separately  below.  In  determining  compensation,  the  compensation  committee
considers all elements of an  executive's total compensation package,  including
change  in  control  arrangements,  participation  in  savings  plans  and other
benefits.

     BASE SALARIES. The compensation committee regularly reviews each  executive
officer's  base salary. The  committee targets the base  salary of the company's
executives to  be  in the  50th  to 75th  percentile  of the  salary  ranges  of
similarly positioned executives in the comparison group of companies.

     Base salaries for executive officers are initially determined by evaluating
the   executives'  levels  of  responsibility,   prior  experience,  breadth  of
knowledge, internal equity issues and external pay practices. Increases to  base
salaries  are driven primarily by performance,  and evaluated based on sustained
levels  of  contribution  to  the  company  in  the  context  of  the  company's
performance-based management process.

     The factors impacting base salary levels are not assigned specific weights.
Rather, the compensation committee reviews all of the factors and makes base pay
determinations  that  reflect  the  compensation  committee's  analysis  of  the
aggregate impact of these factors.

     ANNUAL BONUSES. All employees of the company are eligible to participate in
the company's cash bonus program, with executive employee bonuses determined  by
the  compensation  committee. The  compensation committee  believes that  a cash
bonus program  allows the  company to  communicate specific  goals that  are  of
primary  importance during the  coming year and  motivates executives to achieve
these goals.

     Each year,  the  compensation committee  establishes  specific  performance
goals   in  accordance  with  the   performance-based  management  process,  the
achievement of which determines the funding of  a bonus pool. In turn, the  size
of  the bonus pool determines the amount of the relative awards to participants.
Accordingly, executives' opportunities to earn bonuses correspond to the  degree
to which the pre-established goals are achieved.

     In  general, the  compensation committee  targets the  bonus awards  of the
company's executives to be in the 50th to 75th percentile of the bonus range  of
similarly  positioned executives  in the  comparison group  of companies. Actual
payouts can be above  or below the targeted  levels, depending upon  performance
relative to the pre-established goals.

     At   the  beginning  of  fiscal   year  2003,  the  compensation  committee
established the specific performance  goals upon which  annual bonus awards  for
services  rendered in fiscal year 2003 by our then Chairman, President and Chief
Executive Officer,  our  other named  executive  officers, our  other  executive
officers,  and all employees would be based. Upon completion of the fiscal year,
the compensation committee evaluated the  performance of our executive  officers
in  light of the pre-established performance  goals and determined the amount of
the bonus  award  to be  paid  to each  such  executive. The  performance  goals
established  by  the compensation  committee for  these executives  included the
following criteria: financial goals and business metrics such as revenue,  gross
margin,  market share  and cost management,  business growth  through market and
technology extension, safety, improvement in technology and quality  leadership,
business processes, organizational effectiveness and operational excellence.

     LONG-TERM  INCENTIVES.  Long-term  incentives  are  provided  to executives
pursuant  to  the  Amended  and   Restated  2000  Equity  Incentive  Plan.   The
compensation  committee believes that equity-based  compensation is an essential
element in the company's overall compensation scheme. Equity-based  compensation
is  emphasized in  the design  of the  company's executive  compensation program
because it involves at-risk  components of pay  which directly link  executives'
interests with those of the company's stockholders.

     Initial  or  "new-hire"  options and  restricted  stock may  be  granted to
executive officers when  they first  join the company.  Thereafter, options  and
restricted stock may be granted to each executive officer annually and from time
to time based on performance. To enhance retention, options and restricted stock
granted to executive officers are subject to vesting restrictions that generally
lapse over a four-year period.
                                       -19-


     When  determining  awards  under  the  Amended  and  Restated  2000  Equity
Incentive  Plan,  the  compensation   committee  considers  the  company's   and
individual's   performance  in  the  prior   year,  the  executives'  levels  of
responsibility, prior experience and years of service, historical award data and
compensation practices  at the  comparison group  of companies.  In  determining
award  sizes, the  compensation committee  does not  assign specific  weights to
these factors. Rather, the factors are evaluated on an aggregate basis.

     In this regard, the compensation committee and the board of directors  have
approved  the  Second  Amended and  Restated  2000 Equity  Incentive  Plan which
provides for an increase in the number  of shares of common stock available  for
issuance  under the plan by 3,000,000 shares and recommend that our stockholders
approve the  second  amended  and  restated plan  at  the  annual  meeting.  See
"APPROVAL OF OUR SECOND AMENDED AND RESTATED 2000 EQUITY INCENTIVE PLAN," below.

     Our  executive officers are  also eligible to  participate in the Executive
Officer Deposit Share  Plan. See  "EXECUTIVE COMPENSATION  -- Executive  Officer
Deposit Share Plan," above.

     CEO   COMPENSATION.   The   compensation  committee   used   the  executive
compensation practices described above  to determine Mr. Neville's  compensation
for  fiscal  year  2003, in  consultation  with  outside advisors  hired  by the
committee. In addition, in setting both the cash-based and equity-based elements
of Mr.  Neville's  compensation,  the compensation  committee  made  an  overall
assessment  of  Mr.  Neville's  leadership  in  establishing  and  achieving the
company's long-term and  short-term strategic, operational  and business  goals.
Mr.  Neville's  leadership  during  fiscal year  2003  that  contributed  to the
company's continued solid financial results during the prolonged and significant
downturn in both the  global economy and semiconductor  industry was also  taken
into  consideration in determining his  compensation package. The committee also
considered Mr.  Neville's  decision  to  resign  from  his  roles  as  Chairman,
President  and  Chief  Executive  Officer. In  addition  to  these  factors, Mr.
Neville's bonus  award  reflected  our  performance  against  certain  financial
objectives in fiscal year 2003, which in general met the overall pre-established
goals  for fiscal year 2003. Based upon  all of these criteria, the compensation
committee awarded Mr.  Neville $300,000 as  a cash bonus  for fiscal year  2003,
pursuant  to Mr. Neville's Employment and Transition Agreement with the company,
which together with his  $400,000 annual base salary  effective January 1,  2003
($393,750  paid over fiscal  year 2003), resulted in  total cash compensation to
Mr. Neville for fiscal year  2003 equal to $693,750.  On December 11, 2002,  the
compensation  committee had awarded Mr. Neville equity-based compensation in the
form of  stock  options  to purchase  an  aggregate  of 100,000  shares  of  the
company's  common stock that vest in equal increments upon each anniversary over
fours years and have a term of ten  years that expires December 11, 2012, at  an
exercise  price of $51.37; Mr. Neville has not been granted any additional stock
options since this grant in 2002. Aside from the number of options granted,  the
terms  and conditions of  this option grant  (and for any  other grants that Mr.
Neville had received prior to this grant), are the same as those for grants made
to our other employees, including those  that provide that any options that  are
not vested at the time of the termination of employment are forfeited.

     Since  the  end  of  fiscal  year  2003,  the  compensation  committee,  in
consultation with outside advisors  hired by the  committee, used the  executive
compensation  practices described above  to determine the  terms of Mr. Noglows'
employment offer  and  compensation  for  fiscal year  2004.  Based  upon  these
criteria,  the compensation committee  set Mr. Noglows'  base salary at $450,000
and agreed to pay Mr. Noglows a cash bonus for fiscal year 2004 of not less than
$160,000, following the end of fiscal year 2004. In addition, in connection with
Mr. Noglows'  joining  the  company,  the  compensation  committee  awarded  him
equity-based  compensation in the form of stock options to purchase an aggregate
of 250,000 shares of our  common stock that vest  in equal increments upon  each
anniversary  of the grant date  of November 3, 2003,  Mr. Noglows' date of hire,
over four years and that have a term of ten years that expires November 3, 2013,
at an exercise price of $55.37.

     INTERNAL REVENUE CODE SECTION 162(M). As  one of the factors in its  review
of  compensation matters, the committee  considers the anticipated tax treatment
to our  company and  to our  executives of  various payments  and benefits.  The
deductibility  of some types of compensation payments depends upon the timing of
an executive's vesting  or exercise of  previously granted rights.  Furthermore,
interpretations  of and  changes in  the tax laws  and other  factors beyond the
compensation   committee's   control   also   affect   the   deductibility    of

                                       -20-


compensation.  For these and other reasons,  the compensation committee will not
necessarily limit executive compensation to that deductible under Section 162(m)
of the Internal  Revenue Code of  1986, as amended.  The compensation  committee
will   consider  various   alternatives  to  preserving   the  deductibility  of
compensation payments and benefits to  the extent reasonably practicable and  to
the  extent consistent  with its other  compensation objectives.  In fiscal year
2001, at our annual meeting of stockholders held on March 13, 2001, our  Amended
and  Restated 2000 Equity  Incentive Plan was submitted  to our stockholders for
approval, and  our  stockholders approved  that  plan. At  our  upcoming  annual
meeting  of stockholders, our Second Amended  and Restated 2000 Equity Incentive
Plan will be submitted to our stockholders for approval. The current Amended and
Restated 2000 Equity Incentive Plan and the proposed Second Amended and Restated
2000 Equity Incentive Plan are intended to qualify certain compensation  awarded
under that plan for tax deductibility under Section 162(m).

     Respectfully submitted by the compensation committee,

                              John P. Frazee, Jr.
                               H. Laurance Fuller
                                 J. Joseph King
                           Ronald L. Skates, Chairman
                              Steven V. Wilkinson

                                       -21-


APPROVAL OF SECOND AMENDED AND RESTATED CABOT MICROELECTRONICS CORPORATION 2000
                             EQUITY INCENTIVE PLAN

     Our  board of directors has approved  our Second Amended and Restated Cabot
Microelectronics Corporation 2000 Equity Incentive  Plan, which is an  amendment
of  our  Amended and  Restated  Cabot Microelectronics  Corporation  2000 Equity
Incentive Plan, as  amended in  June 2003 (referred  to below  as the  "Existing
Plan"), for the primary purpose of increasing the number of shares of our common
stock  reserved for issuance  under the plan from  6,500,000 shares to 9,500,000
shares. The Second Amended and Restated  2000 Equity Incentive Plan is  attached
to  this Proxy Statement as Appendix B and is sometimes referred to below as the
"Plan." Our board of directors  has directed that the  Plan be submitted to  our
stockholders at this time for their approval for three reasons in particular:

- to comply with Nasdaq rules, which require such approval,

- to  ensure that the  Plan continues to  satisfy the requirements  set forth in
  Section 162(m) of the Internal Revenue Code of 1986, as amended (the  "Code"),
  and  the  related  regulations with  respect  to  "qualified performance-based
  compensation," and

- to comply with the Existing Plan, which, by its terms, requires such approval.

     In order to  give the company  ongoing flexibility to  attract, retain  and
reward  our employees, directors,  consultants and advisors,  in addition to the
increase in the number of shares from 6,500,000 shares to 9,500,000 shares,  our
board  of  directors  has  approved the  following  material  amendments  to the
Existing Plan:

- the addition of  the ability  for the company  to make  restricted stock  unit
  grants under the Plan;

- an  increase in the number of shares reserved for issuance from 875,000 shares
  of restricted  stock to  1,900,000 shares  of restricted  stock or  restricted
  stock units in the aggregate;

- the  addition  of the  ability for  the  company to  make restricted  stock or
  restricted  stock  unit  awards   that  are  designed   to  qualify  for   the
  performance-based  exception from the tax deductibility limitations of Section
  162(m) of the Code, and  any regulations promulgated thereunder, according  to
  the performance goals described in the Plan; and

- the addition of the ability for participants in the Plan to elect to defer the
  delivery of shares of restricted stock or restricted stock units in order that
  the  participant  would  not  recognize  income  until  the  company  actually
  distributed shares of common stock or cash to the participant.

The other material features of the  Existing Plan remain in the Plan,  including
such  provisions as the specific prohibition on the repricing of options granted
under the Plan.  A description of  certain features of  the Plan, including  the
amended features of the Plan, is included below.

EXISTING PLAN INFORMATION

     Shown  below is  information as  of January  20, 2004  with respect  to the
shares of common stock that may be issued under the Existing Plan. As of January
20, 2004, the closing sale price of  our common stock as reported on the  Nasdaq
National Market was $57.54 per share.

                           EXISTING PLAN INFORMATION




NUMBER OF SECURITIES TO BE ISSUED UPON EXERCISE OF    NUMBER OF SECURITIES REMAINING AVAILABLE FOR FUTURE
     OUTSTANDING OPTIONS, WARRANTS AND RIGHTS                  ISSUANCE UNDER THE EXISTING PLAN
---------------------------------------------------------------------------------------------------------
                                                   
                 4,086,206(1)                                         1,373,627(2)(3)
---------------------------------------------------------------------------------------------------------


-------------------------
(1) Includes  options to purchase 4,082,059 shares of our common stock that have
    been granted under the  Existing Plan and 4,147  shares of restricted  stock
    with  restrictions that have not yet lapsed that have been awarded under the
    Existing Plan.

                                       -22-


(2) Common stock  reserved for  issuance under  the Existing  Plan of  6,500,000
    shares  has  been reduced  by options  to purchase  5,416,611 shares  of our
    common stock  that have  been  granted under  the  Existing Plan  (of  which
    options  to purchase  312,346 shares have  been forfeited  and therefore are
    available for future  grants), and  23,442 shares of  restricted stock  that
    have  been  awarded  under  the  Existing Plan  (of  which  1,334  shares of
    restricted stock have been forfeited and therefore are available for  future
    awards).

(3) Does  not include the proposed increase of available shares under our Second
    Amended and Restated Equity Incentive Plan.

EXISTING EQUITY COMPENSATION PLAN INFORMATION

     Shown below is  information as of  September 30, 2003  with respect to  the
shares of common stock that may be issued under our existing equity compensation
plans.

                 EXISTING EQUITY COMPENSATION PLAN INFORMATION



                                                                                                      (C)
                                            (A)                        (B)               NUMBER OF SECURITIES REMAINING
                                 NUMBER OF SECURITIES TO BE      WEIGHTED-AVERAGE        AVAILABLE FOR FUTURE ISSUANCE
                                  ISSUED UPON EXERCISE OF       EXERCISE PRICE OF       UNDER EQUITY COMPENSATION PLANS
                                    OUTSTANDING OPTIONS,       OUTSTANDING OPTIONS,    (EXCLUDING SECURITIES REFLECTED IN
    PLAN CATEGORY                   WARRANTS AND RIGHTS        WARRANTS AND RIGHTS                COLUMN (A))
-----------------------------------------------------------------------------------------------------------------------------
                                                                                                           
    Equity compensation plans
    approved by security
    holders                              3,145,841(2)                 $51.50                       2,705,399(1)(2)
-----------------------------------------------------------------------------------------------------------------------------
    Equity compensation plans
    not approved by security
    holders                                     --                        --                              --
-----------------------------------------------------------------------------------------------------------------------------
    Total                                3,145,841                    $51.50                       2,705,399
-----------------------------------------------------------------------------------------------------------------------------


-------------------------
(1) Includes  336,830 shares currently  available for future  issuance under our
    Employee Stock  Purchase Plan.  Does not  include the  proposed increase  of
    available  shares  under our  Second Amended  and Restated  Equity Incentive
    Plan.

(2) On November 3, 2003, William P. Noglows was elected Chairman, President  and
    Chief  Executive  Officer  of our  company.  On that  date  the compensation
    committee of the board of  directors approved Mr. Noglows' participation  in
    the  Plan  and further  approved the  grant  of 250,000  non-qualified stock
    options at an exercise price  of $55.37 per share.  The options carry a  ten
    year  term and vest equally over a  four year period, with the first vesting
    on the one year anniversary of the date of the grant.

    On December  1,  2003,  Clifford  L. Spiro  was  appointed  Vice  President,
    Research  and  Development of  our company.  On  that date  the compensation
    committee of the board  of directors approved  Dr. Spiro's participation  in
    the  Plan  and  further approved  the  grant of  50,000  non-qualified stock
    options at an exercise price  of $54.28 per share.  The options carry a  ten
    year  term and vest equally over a  four year period, with the first vesting
    on the one year anniversary of the date of the grant.

    On December 11, 2003, the compensation  committee of the board of  directors
    approved  the fiscal year 2004 grants  of stock options to certain employees
    and executive officers, with  702,200 total options  granted at an  exercise
    price  of $48.91. The options carry a ten  year term and vest equally over a
    four year period, with the first vesting on the one year anniversary of  the
    date of the grant.

AMENDED AND RESTATED 2000 EQUITY INCENTIVE PLAN BENEFITS

     At  this time, specific benefits or amounts  to be received or allocated to
named executive  officers,  current  executive  officers  as  a  group,  current
directors who are not executive officers as a group and all employees, including
all current officers who are not executive officers, as a group pursuant to this
Plan  are  not  determinable. However,  for  the purposes  of  illustration, the
following table sets forth the benefits and amounts

                                       -23-


that were granted to the named executive officers, current executive officers as
a  group, current directors  who are not  executive officers as  a group and all
current  employees,  including  all  current  officers  who  are  not  executive
officers, as a group during the fiscal year ended September 30, 2003 pursuant to
the Existing Plan.

            AMENDED AND RESTATED 2000 EQUITY INCENTIVE PLAN BENEFITS




                                                                                                NUMBER OF SHARES OF
                                            DOLLAR          NUMBER OF    NUMBER OF SHARES OF     RESTRICTED STOCK
          NAME AND POSITION             VALUE (1) ($)        OPTIONS      RESTRICTED STOCK         PAID IN FULL
-----------------------------------------------------------------------------------------------------------------------
                                                                                                  
    Matthew Neville, Former
    President and Chief Executive
    Officer                                 621,986          100,000             318                    212
-----------------------------------------------------------------------------------------------------------------------
    William P. Noglows, President
    and Chief Executive Officer            --                  --            --                     --
-----------------------------------------------------------------------------------------------------------------------
    Daniel J. Pike, Vice President
    of Operations                           333,180           54,000         --                     --
-----------------------------------------------------------------------------------------------------------------------
    H. Carol Bernstein, Vice
    President, Secretary and
    General Counsel                         293,075           47,500         --                     --
-----------------------------------------------------------------------------------------------------------------------
    Stephen R. Smith, Vice
    President of Marketing and
    Sales                                   351,690           57,000         --                     --
-----------------------------------------------------------------------------------------------------------------------
    J. Michael Jenkins, Vice
    President of Human Resources            298,061           47,500             318                    212
-----------------------------------------------------------------------------------------------------------------------
    All current executive officers
    as a group                            2,391,714          330,750             318                    212
-----------------------------------------------------------------------------------------------------------------------
    All current directors who are
    not executive officers as a
    group                                   864,000           45,000         --                     --
-----------------------------------------------------------------------------------------------------------------------
    All current employees,
    including current officers who
    are not executive officers, as
    a group                               3,578,311          539,760             318                    212
-----------------------------------------------------------------------------------------------------------------------


-------------------------
(1) Dollar Value is based upon the total dollar value for options and restricted
    stock.  For the  purposes of illustration,  the dollar value  of options has
    been computed based  upon the  difference between  the price  of our  common
    stock  as of January 20,  2004, which was $57.54,  and the exercise price of
    the options. The dollar value of  restricted stock awards has been  computed
    based  upon the closing price for the shares  of common stock on the date of
    grant. We ascribe  no value  to restricted  stock in  the Executive  Officer
    Deposit Share Plan for which full value was paid.

DESCRIPTION OF THE SECOND AMENDED AND RESTATED 2000 EQUITY INCENTIVE PLAN

     The  purposes  of the  Plan are  to  enhance our  company's ability  to (a)
attract and retain employees, directors, consultants  and advisors who are in  a
position  to make significant  contributions to the success  of our company; (b)
reward  these  individuals   for  these  contributions;   (c)  encourage   these
individuals  to take into account the long-term interests of our company and its
stockholders; and (d) reward individuals  who have contributed to our  company's
success, in each case, through ownership of shares of our common stock.

     Our  board of  directors and  our compensation  committee believe  that the
grant of equity  incentives is  an essential  component of  compensation and  is
standard  and expected in our industry. They  also believe that awards under the
Existing Plan have played an important part in enabling the company to  attract,
retain and

                                       -24-


motivate  employees in the extremely competitive,  high growth industry in which
we operate.  The ability  to continue  to attract  new employees  and to  retain
current  employees is a critical element in  our strategy for future growth, and
our ability  to attract  and  retain qualified  employees  could be  impeded  if
sufficient equity incentives are not available in the future for grant under the
Plan.  Furthermore,  the ability  to motivate  and  incent employees  and senior
management to take into account the  long-term interests of our company and  its
stockholders  is also  essential to  our future  growth, and  our ability  to so
motivate and incent  our employees  and senior  management could  be impeded  if
sufficient equity incentives are not available in the future.

     With  these matters  in mind, the  board of directors  and the compensation
committee engaged an outside advisor to assist in an evaluation of the  Existing
Plan,  in general, and the adequacy of  the number of shares available under the
Existing Plan (prior to the proposed amendment and restatement), in  particular.
The advisor conducted a study of the Existing Plan and a comparative analysis of
similar  plans of peer companies in our industry. The advisor also evaluated the
adequacy of the number of equity awards available under the Existing Plan to our
executive officers, senior managers  and other employees in  light of our  goals
for  attracting, retaining, rewarding  and incenting our  employees as described
above.

     In addition, in the  past year, the availability  of shares under the  plan
has been important in allowing us to attract and incent high quality executives,
such  as Mr. Noglows, our new President and Chief Executive Officer, Mr. William
S. Johnson, our Vice President and  Chief Financial Officer, and Dr. Spiro,  our
Vice President of Research and Development, to join our company. In this regard,
it is especially important that the number of shares available under the Plan be
sufficient  to  allow  us to  continue  to  attract and  retain  other executive
officers and senior managers, as Mr. Noglows continues to refine the composition
of his executive team.

     Based in significant  part on  all of  these factors  and the  consultant's
conclusions  and advice, our board of  directors believes that, while the number
of shares available under the Existing Plan (prior to the proposed amendment and
restatement) is  expected  to  be  sufficient during  the  next  twelve  months,
additional  shares will  be required  soon thereafter  to enable  the company to
continue realizing  the  plan's intended  benefits.  Accordingly, our  board  of
directors  recommends that stockholders approve  the Second Amended and Restated
Cabot Microelectronics Corporation 2000 Equity Incentive Plan.

     The following description of certain features  of the Plan is qualified  in
its entirety by reference to the full text of the Plan.

     GENERAL;  SHARES AVAILABLE FOR ISSUANCE UNDER THE PLAN. The Plan enables us
to make  awards of  options,  restricted stock  and  restricted stock  units  to
eligible  employees, directors, consultants and advisers  of our company and our
affiliates. We believe that the Plan  provides us with flexibility in  designing
and providing incentive compensation to Plan participants. Subject to adjustment
for  stock splits  and similar  events, the maximum  number of  shares of common
stock that may be issued  under the Plan is  9,500,000 shares. This number  does
not  include shares that will become available  under the Plan because of events
such as forfeitures. In addition, awards  granted through the assumption of,  or
in  substitution  or  exchange  for,  similar  awards  in  connection  with  the
acquisition of another corporation or business  entity shall not be counted  for
purposes  of applying the limitations of this section on the number of shares of
common stock available  for awards  generally or  any particular  kind of  award
under the Plan.

     ADMINISTRATION;  ELIGIBLE GRANTEES. The compensation committee of the board
of directors administers the  Plan and has the  sole discretion to construe  and
interpret the Plan and any awards made under the Plan. These interpretations are
binding  on our company and on the Plan participants. The compensation committee
also determines the  Plan participants who  will receive awards,  the number  of
shares  subject to such awards and the  terms and conditions of each such award.
It may make any amendment or modification to any award agreement consistent with
the terms  of the  Plan and  relevant rules  and regulations.  The  compensation
committee  currently  consists  of  five independent  members  of  our  board of
directors, all of  whom meet the  Nasdaq and SEC  criteria for independence  and
none  of whom are employees of our company. Officers and other employees as well
as our directors, advisors and consultants are eligible to receive awards  under
the Plan,

                                       -25-


but no  participant may  receive awards  under  the Plan  in any  calendar  year
covering more than 300,000 shares of common stock.

     As  of January 20, 2004, there  were approximately nine officers, 257 other
employees, and six independent, non-employee  directors who are participants  in
the  plan. We estimate that approximately  575 persons are currently eligible to
receive awards under the Plan.

     In addition,  the compensation  committee may  grant substitute  awards  of
"incentive stock options" or "ISOs" as defined in Section 422 of the Code, stock
options that are not intended to qualify under Section 422 of the Code ("NQSOs")
or  shares of  our restricted  stock or  restricted stock  units to  persons who
become our employees in connection with business acquisitions. These  substitute
awards  would replace  equity incentives held  by these persons  in the acquired
entity or the selling business.

     AWARDS. Under the  Plan, we are  permitted to  make awards in  the form  of
ISOs, NQSOs and shares of restricted common stock and restricted stock units.

        STOCK  OPTIONS. The compensation committee may grant stock options under
        the Plan. Stock  options enable  the holder  of the  option to  purchase
        shares  of our  common stock  at a  price specified  by the compensation
        committee at the time the award  is made. The Plan permits the  granting
        of  stock options that qualify as ISOs  under Section 422 of the Code as
        well as NQSOs. The compensation committee may grant ISOs to purchase  up
        to 1,750,000 shares of our common stock under the Plan. The compensation
        committee determines the exercise price of all stock options which, as a
        general  rule with respect to ISOs, may not be less than the fair market
        value of a share of common stock  at the time of grant. In practice,  to
        date  the compensation committee  has only granted  NQSOs at an exercise
        price that is equal to the fair market value of a share of common  stock
        at the time of grant and has not granted any ISOs. The Plan specifically
        prohibits  the  repricing of  options.  The compensation  committee also
        determines when an option may be  exercised and its term, which may  not
        exceed ten years.

        RESTRICTED  STOCK.  The  compensation  committee also  may  award  up to
        1,900,000 shares of restricted stock and restricted stock units ("RSUs")
        in the aggregate  (see below) under  the Plan. In  general, an award  of
        restricted  stock  entitles the  recipient  to shares  of  common stock,
        subject to restrictions  determined by the  compensation committee.  The
        compensation  committee may  require the recipient  to pay consideration
        for the restricted stock as a  condition to the grant of the  restricted
        stock.  Restrictions  on  restricted  stock lapse  as  specified  by the
        compensation committee  at the  time of  grant. Until  the  restrictions
        lapse,  shares  of  restricted  stock  are  non-transferable. Generally,
        recipients of restricted  stock have  all rights of  a stockholder  with
        respect  to the  shares, including  voting and  dividend rights, subject
        only  to  the  conditions  and  restrictions  generally  applicable   to
        restricted  stock or  to other restrictions  and conditions specifically
        set forth  in the  award agreement.  An award  of restricted  stock  may
        provide for the right to receive on the payment date for any dividend on
        the  stock, cash compensation from the company (a "dividend equivalent")
        equal to  the dividend  that would  have  been paid  on such  shares  of
        restricted  stock if such shares  had been fully vested  and held by the
        participant on the record date for payment of such dividend.

        RESTRICTED STOCK UNITS. As stated above, the compensation committee also
        may award RSUs under the Plan, which together with awards of  restricted
        stock, may not exceed 1,900,000 units or shares. In general, an award of
        RSUs  entitles the recipient to a  contingent right to receive shares of
        common stock  (or  the  cash  equivalent)  in  the  future,  subject  to
        restrictions  determined by the compensation committee. The compensation
        committee may  require  the  recipient  to  pay  consideration  for  the
        restricted  stock as a condition to  the grant of the RSUs. Restrictions
        on RSUs lapse as specified by the compensation committee at the time  of
        grant.  RSUs  are  non-transferable.  The  compensation  committee  will
        specify in the award agreement whether the recipient of RSUs has any  of
        the  rights of a stockholder with  respect to the RSUs, including voting
        and dividend  rights. An  award of  RSUs may  provide for  the right  to
        receive  on  the  payment date  for  any  dividend on  the  common stock
        underlying the  RSU, cash  compensation from  the company  (a  "dividend
        equivalent")  equal to  the dividend  that would  have been  paid on the
        shares   underlying    such   RSUs    if    such   shares    had    been
                                       -26-


        issued  and outstanding, fully vested and held by the participant on the
        record date for payment of such dividend.

     EFFECT OF TERMINATION  OF SERVICE. As  a general rule,  a termination of  a
Plan  participant's service  with the company  will result in  the forfeiture of
unvested options, restricted  stock, and  restricted stock  units, although  the
compensation  committee may depart from this general rule by providing otherwise
in individual  award agreements  or by  amending existing  award agreements.  In
particular, the compensation committee has substantial discretion to address the
effect  of service termination upon the vesting of stock options (and the period
during which they may be exercised), restricted stock and RSUs. Generally, under
policies established by the compensation committee, in the event of the death or
disability of a Plan participant, we will permit the Plan participant or his  or
her  heirs up to three years  (one year in the case  of ISOs) to exercise vested
options following such death or disability, but in any event such exercise  must
be  made  before  the  expiration  of  the  original  term  of  the  award.  The
compensation committee may terminate and recover any Plan award if either (1)  a
Plan  participant provides  services to a  competitor of the  company within six
months of  exercising  an  option  or  terminating  service  with  the  company,
discloses  confidential information, engages in conduct that constitutes "Cause"
or other circumstances (as defined in the Plan) for award termination or (2) the
company terminates the Plan  participant's service for "Cause."  In the case  of
any  such award  termination or  recovery, the  Plan participant  is required to
disgorge his or her gains on the sale of any common stock he or she received  as
a  result of a Plan award. In  general, if a Plan participant terminates service
with the company other  than for Cause, disability  or death, we will  generally
permit  such participant  from one  to three  months to  exercise vested options
following the date of termination, but in  any event such exercise must be  made
before the expiration of the original term of the award.

     ADJUSTMENTS   FOR  CHANGES  IN  CAPITALIZATION;   CHANGE  IN  CONTROL.  The
compensation committee may make appropriate adjustments to the number of  shares
of  our common  stock that may  be delivered  under the Plan  and to outstanding
awards to reflect  stock dividends,  stock splits,  and similar  changes in  our
capitalization.  When granting awards under the Plan, the compensation committee
may provide  for the  accelerated  vesting of  options,  and for  the  immediate
lapsing  of  restrictions on  restricted  stock in  the  event of  a  "Change in
Control." The term "Change in Control" is defined in the Plan, and includes:

- the occurrence of a  person or entity  becoming a beneficial  owner of 30%  or
  more of the voting power of our common stock;

- the  merger of our company with another company (except where our stockholders
  would hold at least  60% of the  voting power of our  common stock after  such
  merger);

- certain significant changes to the composition of our board of directors; and

- the liquidation of our company.

     AMENDMENT  AND  TERMINATION. The  compensation  committee may  at  any time
discontinue granting awards under  the Plan. Our board  of directors may at  any
time  amend the Plan or  terminate the Plan as to  any further grants of awards.
However, none of these  actions may, without the  approval of our  stockholders,
increase  the maximum number of shares of common stock available under the Plan,
extend the time within which awards may be granted, amend the provisions of  the
Plan  relating to amendments, or  otherwise make any amendments  that by rule or
regulation may be made only subject to the approval of stockholders, nor may any
of these  actions adversely  affect the  rights of  a holder  of any  previously
granted award.

     CERTAIN  FEDERAL INCOME TAX  CONSEQUENCES. Following is  a brief summary of
the principal federal  income tax consequences  of awards under  the Plan.  This
summary  is not an  exhaustive description and does  not describe all applicable
federal, state or local tax laws.

        ISOS. A Plan  participant is not  subject to federal  income tax at  the
        time of either the grant or the exercise of an ISO. In the year in which
        an  ISO is exercised, however, the amount by which the fair market value
        of the shares of common stock received on the exercise of an ISO exceeds
        the exercise price will constitute an adjustment to the option  holder's
        income in computing alternative minimum

                                       -27-


        taxable  income. If an option holder does  not dispose of such shares of
        common stock within  two years  after the ISO  was granted  or one  year
        after  the  ISO  was  exercised, whichever  is  later  (a "disqualifying
        disposition"), then any  gain or loss  recognized upon such  disposition
        generally  will be  treated as long-term  capital gain or  loss. In such
        event, our  company will  not  receive a  tax  deduction on  either  the
        exercise of the ISO or on the sale of the underlying common stock.

        If  an option holder  makes a disqualifying disposition,  he or she will
        realize ordinary income in an amount equal to the lesser of (i) the fair
        market value of the option shares on the date the ISO is exercised minus
        the exercise  price, or  (ii) the  sales price  received by  the  option
        holder on the disposition of the option shares minus the exercise price.
        In  such event, our company will be entitled to a deduction in an amount
        equal to the ordinary income realized by the option holder. If a sale is
        a  disqualifying  disposition,  the  option  holder  also  may   realize
        short-term  or long-term capital gain or  loss if such shares constitute
        capital assets in his or her hands. The gain or loss will be measured by
        the difference between the fair market value of the option shares on the
        date of exercise of the ISO and the sales price of the shares.

        NQSOS. No income is realized  by an option holder  upon the grant of  an
        NQSO.  Upon the exercise  of an NQSO,  however, the amount  by which the
        fair market value of the option  shares on the date of exercise  exceeds
        the  exercise price will be taxed as ordinary income to an option holder
        and our company will be entitled to a deduction in an equal amount. Upon
        subsequent sales  of the  option shares,  an option  holder may  realize
        short-term or long-term capital gain or loss, depending upon the holding
        period  of the  shares, if such  shares constitute capital  assets in an
        option holder's  hands.  The  gain  or loss  will  be  measured  by  the
        difference between the sales price and the tax basis of the shares sold.
        The tax basis for this purpose will be the sum of the exercise price and
        the  amount of ordinary income realized by the option holder as a result
        of his or her exercise of the option.

        RESTRICTED  STOCK.  Generally,  no  income  is  realized  when  a   Plan
        participant  is granted restricted stock  until the restrictions imposed
        lapse  and  the  stock  becomes  transferable.  However,  if  the   Plan
        participant  makes a Section  83(b) election to have  the grant taxed as
        compensation income  at fair  market value  on the  date of  grant,  any
        future  appreciation (or depreciation) in the value of the stock subject
        to the grant will  be taxed as  capital gain (or loss)  at the time  the
        stock is sold.

        RESTRICTED  STOCK UNITS.  Generally, no income  is realized  when a Plan
        participant is granted restricted stock units ("RSUs") or when the  RSUs
        vest,  until the value of the RSUs  is distributed to the participant in
        cash or common stock.

        SECTION 162(M).  Section 162(m)  of the  Code limits  the  deductibility
        (under  certain circumstances)  of compensation  that exceeds $1,000,000
        annually that we pay to our chief executive officer and to our four most
        highly compensated officers (other than the chief executive officer)  as
        determined  at  the end  of  our taxable  year.  Section 162(m)  and its
        regulations provide certain exclusions from the amounts included in  the
        $1,000,000   limitation,  including  compensation   that  is  "qualified
        performance-based compensation" within the  meaning of the  regulations.
        The  Plan generally is intended to satisfy the requirements set forth in
        the   regulations   with   respect   to   "qualified   performance-based
        compensation"  with  respect  to  options  that  are  exercisable  at an
        exercise price of not less than 100% of the fair market value of a share
        of our common  stock on  the date  of grant.  However, if  an option  is
        exercisable  at a price  less than 100% of  the price of  a share of our
        common stock on the date of grant, the compensatory element of such NQSO
        (i.e., the excess  of such fair  market value over  the exercise  price)
        will not constitute "qualified performance-based compensation."

        If the compensation committee grants restricted stock or RSU awards that
        are designed to qualify for the performance-based exception from the tax
        deductibility  limitations Section 162(m) of  the Code, the compensation
        committee may determine the number  of shares awarded and/or vesting  of
        such  restricted stock or  RSU awards using  performance measures, which
        may include such measures as  financial goals and business metrics  such
        as  revenue, gross  margin, net  income, operating  income, earnings per
        share, return on operating assets  or capital, cash flow, market  share,
                                       -28-


        return  to shareholders, cost management, business growth through market
        and technology extension, safety, improvement in technology and  quality
        leadership,   business   processes,  organizational   effectiveness  and
        operational excellence  and/or other  performance  measures set  by  the
        board  of directors or  the compensation committee.  In addition, in the
        event that the compensation committee determines that it is advisable to
        grant restricted  stock or  RSU  awards that  may  not qualify  for  the
        performance-based  exception, the  compensation committee  may make such
        grants without satisfying the requirements of Section 162(m) of the Code

        DEFERRAL. A participant  may elect to  defer the delivery  of shares  of
        restricted  stock or  RSUs until the  termination of his  or her service
        with the  company, or  some other  date. Generally,  if the  participant
        elects  to defer  delivery, the  participant would  not recognize income
        until the company actually distributes shares of common stock or cash to
        the participant.

     MISCELLANEOUS. The Plan is not qualified under Section 401 of the Code.  In
addition,  the Plan  is not  subject to  any of  the provisions  of the Employee
Retirement Income Security Act of 1974, as amended.

     If the Second Amended and Restated Cabot Microelectronics Corporation  2000
Equity  Incentive Plan is not approved by  our stockholders, we will continue to
administer and maintain the Existing Plan in its current form.

OUR BOARD OF DIRECTORS RECOMMENDS THAT YOU VOTE "FOR" THE APPROVAL OF THE SECOND
AMENDED AND RESTATED  CABOT MICROELECTRONICS CORPORATION  2000 EQUITY  INCENTIVE
PLAN.

                 CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

Indemnification

     Our bylaws and our certificate of incorporation require us to indemnify our
directors  and officers to the fullest extent authorized by the Delaware General
Corporation Law. We have entered into indemnification agreements with all of our
directors and executive  officers in which  we confirm that  we will provide  to
them  the  indemnification  rights provided  for  in  our by-laws  and  agree to
maintain directors' and officers' liability insurance on their behalf.

                                       -29-


                               PERFORMANCE GRAPH

     The following graph illustrates the cumulative total stockholder return  on
our  common  stock during  the  period from  our IPO  on  April 4,  2000 through
September 30,  2003 and  compares it  with the  cumulative total  return on  the
NASDAQ  Stock Market (U.S.) Index and  the Philadelphia Semiconductor Index. The
comparison assumes $100 was invested on April 4, 2000 in our common stock and in
each of the foregoing indices and assumes reinvestment of dividends, if any. The
performance shown is not necessarily indicative of future performance.

                COMPARISON OF 42 MONTH CUMULATIVE TOTAL RETURN*
                   AMONG CABOT MICROELECTRONICS CORPORATION,
                      THE NASDAQ STOCK MARKET (U.S.) INDEX
                    AND THE PHILADELPHIA SEMICONDUCTOR INDEX

                              [PERFORMANCE GRAPH]


                                                                      CUMULATIVE TOTAL RETURN
                                      ---------------------------------------------------------------------------------------
                                      4/4/00    4/00     5/00     6/00     7/00     8/00     9/00    10/00    11/00    12/00
                                      ------   ------   ------   ------   ------   ------   ------   ------   ------   ------
                                                                                         
Cabot Microelectronics
 Corporation........................  100.00   162.50   163.75   228.75   235.00   291.88   240.00   220.94   183.75   259.69
NASDAQ Stock Market (U.S.)..........  100.00   100.00    87.94   103.38    97.77   109.33    95.13    87.32    67.27    63.70
Philadelphia Semiconductor..........  100.00   100.99    92.83    98.17    93.01   104.81    67.11    66.41    52.69    49.53


                                               CUMULATIVE TOTAL RETURN
                                      ------------------------------------------
                                       1/01     2/01     3/01     4/01     5/01
                                      ------   ------   ------   ------   ------
                                                           
Cabot Microelectronics
 Corporation........................  424.07   302.82   221.25   320.10   321.30
NASDAQ Stock Market (U.S.)..........   71.43    55.30    47.55    54.64    54.58
Philadelphia Semiconductor..........   58.82    43.77    42.84    51.06    45.50



                                                                        CUMULATIVE TOTAL RETURN
                                        ----------------------------------------------------------------------------------------
                                         6/01      7/01     8/01     9/01    10/01    11/01    12/01     1/02     2/02     3/02
                                        -------   ------   ------   ------   ------   ------   ------   ------   ------   ------
                                                                                            
Cabot Microelectronics Corporation....   310.00   351.25   350.25   241.55   331.40   346.80   396.25   331.40   275.20   338.25
NASDAQ Stock Market (U.S.)............    56.04    52.48    46.76    38.88    43.87    50.11    50.54    50.13    44.92    47.86
Philadelphia Semiconductor............    47.72    48.43    45.36    32.46    38.16    46.69    45.09    48.98    42.88    47.51


                                                      CUMULATIVE TOTAL RETURN
                                        ---------------------------------------------------
                                         4/02     5/02     6/02     7/02     8/02     9/02
                                        ------   ------   ------   ------   ------   ------
                                                                   
Cabot Microelectronics Corporation....  244.50   243.90   215.80   211.70   212.25   186.20
NASDAQ Stock Market (U.S.)............   43.89    41.96    38.16    34.67    34.30    34.30
Philadelphia Semiconductor............   43.89    41.86    31.62    29.34    26.55    21.67



                                                                    CUMULATIVE TOTAL RETURN
                                        -------------------------------------------------------------------------------
                                         10/02    11/02    12/02     1/03     2/03     3/03     4/03     5/03     6/03
                                        -------   ------   ------   ------   ------   ------   ------   ------   ------
                                                                                      
Cabot Microelectronics Corporation....   226.95   301.75   236.00   219.50   210.00   209.70   216.10   231.35   252.15
NASDAQ Stock Market (U.S.)............    32.36    35.96    32.48    32.13    32.58    32.67    35.64    38.77    39.39
Philadelphia Semiconductor............    28.24    34.19    25.85    25.15    27.27    26.53    29.72    34.33    33.57


                                        CUMULATIVE TOTAL RETURN
                                        ------------------------
                                         7/03     8/03     9/03
                                        ------   ------   ------
                                                                         
Cabot Microelectronics Corporation....  310.55   325.95   278.15
NASDAQ Stock Market (U.S.)............   42.11    43.94    43.37
Philadelphia Semiconductor............   37.33    43.44    41.07


-------------------------
* $100 invested  on  4/4/00 in  stock  or  index --  including  reinvestment  of
  dividends.
  Fiscal year ending September 30.

                                       -30-


                      2005 ANNUAL MEETING OF STOCKHOLDERS

     The 2005 annual meeting of stockholders  is presently scheduled to be  held
on  March 8, 2005. Any  proposals of stockholders intended  for inclusion in the
proxy statement for our 2005 annual meeting of stockholders must be received  by
the  Secretary of our company at our offices at 870 North Commons Drive, Aurora,
Illinois 60504, by Tuesday, September 28, 2004. If a stockholder of the  company
intends  to present a proposal at the  2005 annual meeting of stockholders, such
stockholder must comply with the advance notice provisions of our by-laws. Those
provisions require that such proposal must  be received by the Secretary of  our
company  at our offices at 870 North  Commons Drive, Aurora, Illinois 60504, not
earlier than Tuesday, November 9, 2004 and not later than Thursday, December  9,
2004.  Subject to  certain exceptions set  forth in our  by-laws, such proposals
must contain specific information concerning the  person to be nominated or  the
matters  to  be  brought  before  the  meeting  and  concerning  the stockholder
submitting the proposal.

                       "HOUSEHOLDING" OF PROXY MATERIALS

     The SEC has adopted  rules that permit  companies and intermediaries  (e.g.
brokers)  to satisfy the delivery requirements for proxy statements with respect
to two or  more stockholders  sharing the same  address by  delivering a  single
proxy statement addressed to those stockholders. This process, which is commonly
referred   to  as  "householding,"  potentially   means  extra  convenience  for
stockholders and cost savings for companies.

     A number  of  brokers with  accountholders  who are  stockholders  will  be
"householding"  our  proxy  materials.  As indicated  in  the  notice previously
provided by these  brokers to  stockholders, a  single proxy  statement will  be
delivered   to  multiple   stockholders  sharing  an   address  unless  contrary
instructions have  been received  from an  affected stockholder.  Once you  have
received  notice  from  your  broker  or us  that  they  will  be "householding"
communications to  your  address, "householding"  will  continue until  you  are
notified otherwise.

     Stockholders  who currently receive multiple  copies of the proxy statement
at  their  address   and  would   like  to  request   "householding"  of   their
communications  should contact  their broker  or, if  a stockholder  is a direct
holder of shares of our  common stock, they should  submit a written request  to
our   transfer  agent,  Equiserve  Trust  Company,  N.A.,  at  P.O.  Box  43010,
Providence, Rhode Island 02940-3010 Attention: Shareholder Inquiries.

                  VOTING THROUGH THE INTERNET OR BY TELEPHONE

     Our stockholders voting through the  Internet should understand that  there
may  be  costs associated  with electronic  access, such  as usage  charges from
Internet access providers  and telephone companies,  that must be  borne by  the
stockholder.  Those  of our  stockholders with  shares registered  directly with
Equiserve, the  company's transfer  agent, may  vote telephonically  by  calling
Equiserve  at (877) 779-8683, or may vote  through the Internet at the following
address on the World Wide Web:

     www.eproxyvote.com/ccmp

                                       -31-


[CABOT MICROELECTRONICS LOGO]

                                                                      APPENDIX A
                                                         AUDIT COMMITTEE CHARTER

                       CABOT MICROELECTRONICS CORPORATION
                            AUDIT COMMITTEE CHARTER

PURPOSE

     The purpose  of the  Audit  Committee (the  "Committee")  of the  Board  of
Directors (the "Board") of Cabot Microelectronics Corporation (the "Company") is
to  oversee the Company's  accounting and financial  reporting processes and the
audit of its financial statements.  The Committee is responsible for  overseeing
the  Company's  accounting  and system  of  internal controls,  the  quality and
integrity  of  the  Company's  financial   reports  and  the  independence   and
performance  of the Company's independent public accountants responsible for the
annual audit  and  quarterly  reviews  of  the  Company's  financial  statements
("outside auditor"). In so doing, the Committee should endeavor to maintain free
and  open means  of communication  between the  members of  the Committee, other
members of the Board, the outside  auditor, the senior and financial  management
of  the Company, and with any employees  of the Company or other individuals who
desire to bring  accounting, internal  accounting controls,  auditing, or  other
matters to the Committee's attention.

     In  the exercise of its  oversight responsibilities, it is  not the duty of
the Committee  to plan  or conduct  audits or  to determine  that the  Company's
financial statements fairly present the Company's financial position and results
of   operation  and  are  in   accordance  with  generally  accepted  accounting
principles. Instead, such duties remain the responsibility of management and the
outside auditor.  Nothing contained  in this  charter is  intended to  alter  or
impair  the  operation of  the "business  judgment rule"  as interpreted  by the
courts under the Delaware General Corporation Law. Further, nothing contained in
this charter is  intended to alter  or impair the  right of the  members of  the
Committee  under the  Delaware General Corporation  Law to  rely, in discharging
their responsibilities, on the records of  the Company and on other  information
presented  to the  Committee, Board  or Company by  officers of  employees or by
outside experts such as the outside auditor.

MEMBERSHIP

     The Committee shall  consist of at  least three members  of the Board.  The
members  shall  be appointed  by  action of  the Board  and  shall serve  at the
discretion of the Board. Each Committee member shall satisfy the  "independence"
and  other  requirements  of  relevant  law,  including  rules  adopted  by  the
Securities  and  Exchange  Commission  ("SEC"),  and  the  Nasdaq  Stock  Market
("Nasdaq").  At least one  member of the Committee  shall satisfy the "financial
expert" requirements of relevant  law, including rules adopted  by the SEC,  and
Nasdaq.  Each  member of  the Committee  shall  be able  to read  and understand
financial statements at the time of his or her appointment.

COMMITTEE ORGANIZATION AND PROCEDURES

     1. The Chair of the Committee shall  be appointed by the Board by  majority
vote.  The Chair (or  in his or her  absence, a member  designated by the Chair)
shall preside at all meetings of the Committee.

     2. The Committee shall  have the authority to  establish its own rules  and
procedures  consistent with the bylaws of the  Company for notice and conduct of
its meetings, should the Committee, in  its discretion, deem it desirable to  do
so. Members of the Committee may participate telephonically in any meeting.

     3.  The  Committee  shall  meet  as  frequently  as  the  Committee  in its
discretion deems desirable.

                                       A-1


     4. The Committee may, in its discretion, include in its meetings members of
the Company's  management,  representatives  of  the  outside  auditor,  outside
counsel,  the  senior internal  audit manager  and  other personnel  employed or
retained by the Company, the Board or the Committee. The Committee may meet with
the outside auditor or the senior internal audit manager, internal audit service
provider, outside counsel or  other advisors in  separate executive sessions  to
discuss  any matters that the Committee  believes should be addressed privately,
without management's presence.  The Committee may  likewise meet privately  with
management, as it deems appropriate.

     5. The Committee may, in its discretion, retain and utilize the services of
the  Company's regular corporate legal counsel  with respect to legal matters or
its other advisors with respect to  other matters or, at its discretion,  retain
other  legal counsel  or other  advisors if it  determines that  such counsel or
advice is necessary or appropriate under the circumstances.

     6. The Committee shall have its own funding from the Company to pay for the
services of  the Company's  outside  auditors and  any  legal counsel  or  other
advisors that are retained by the Committee.

RESPONSIBILITIES

  Outside Auditor

     7.  The Committee  has the  sole and  direct responsibility  for selecting,
appointing, terminating,  compensating  and  overseeing  the  Company's  outside
auditor, as well as for resolving any disagreements between the outside auditors
and  management.  The Committee  shall only  retain as  outside auditor  a firm,
including representatives of the firm responsible for the Company's audit,  that
meets  the requirements of relevant law,  the Public Accounting Oversight Board,
the SEC and Nasdaq. The outside  auditor shall be ultimately accountable to  the
Committee for all matters, including the audit of the Company's annual financial
statements  and  related  services.  The  Committee  shall  select,  appoint and
periodically evaluate the performance of the outside auditor and, if  necessary,
replace the outside auditor. At the discretion of the Committee or to the extent
required  by relevant law, Nasdaq  or the SEC, the  Committee shall recommend to
the Board the nomination of the outside auditor for stockholder approval at  any
meeting of stockholders.

     8.  The Committee  shall approve  the fees  to be  paid to  the outside (or
other) auditor(s)  and any  other terms  of the  engagement of  the outside  (or
other)  auditor for any and all  services (whether audit or non-audit services),
to be provided by the  outside (or other) auditor,  in advance of such  services
being  provided. The Committee may delegate such pre-approval of services to the
Committee Chair, and the Committee  Chair shall provide subsequent  notification
to  the  Committee  of  any  such  pre-approval  at  scheduled  meetings  of the
Committee.

     9. The Committee  shall receive  from the  outside auditor  and review,  at
least  annually, a written  statement delineating all  relationships between the
outside auditor and  the Company, consistent  with Independence Standards  Board
Standard  1. The Committee shall actively engage  in a dialogue with the outside
auditor with respect  to any disclosed  relationships or services  that, in  the
view  of  the Committee,  may  impact the  objectivity  and independence  of the
outside auditor. If the Committee determines that further inquiry is  advisable,
the  Committee  shall take  any appropriate  action in  response to  the outside
auditor's report to satisfy itself of the auditor's independence.

  Annual Audit

     10. The Committee shall meet with the outside auditor and management of the
Company in connection with each annual audit  to discuss the scope of the  audit
and the procedures to be followed.

     11. The Committee shall review and discuss the audited financial statements
with the management of the Company.

     12.  The  Committee  shall discuss  with  the outside  auditor  the matters
required to be discussed by  Statement on Auditing Standards  No. 61 as then  in
effect  including,  among  others,  (i)  the methods  used  to  account  for any
significant unusual transaction reflected  in the audited financial  statements;
(ii) the effect of

                                       A-2


significant  and critical accounting  policies in any  controversial or emerging
areas for which there is a lack  of authoritative guidance or a consensus to  be
followed  by  the  outside auditor;  (iii)  the  process used  by  management in
formulating particularly sensitive  accounting estimates and  the basis for  the
auditor's  conclusions regarding the reasonableness of those estimates; and (iv)
any disagreements with management over the application of accounting principles,
the basis  for  management's accounting  estimates  or the  disclosures  in  the
financial statements.

     13.  The Committee shall, based on the review and discussions in paragraphs
11 and 12 above, and based on the disclosures received from the outside  auditor
regarding  its  independence and  discussions  with the  auditor  regarding such
independence in paragraph 9  above, recommend to the  Board whether the  audited
financial  statements should be included in  the Company's Annual Report on Form
10-K for the fiscal year subject to the audit.

  Quarterly Review

     14. The  outside  auditor  is  required to  review  the  interim  financial
statements  to be included  in any Form  10-Q of the  Company using professional
standards  and  procedures  for  conducting  such  reviews,  as  established  by
generally  accepted auditing standards  as modified or  supplemented by the SEC,
prior to  the  filing  of  the  Form 10-Q.  The  Committee  shall  discuss  with
management  and the outside  auditor in person,  at a meeting,  or by conference
telephone call, the results  of the quarterly review  including such matters  as
significant adjustments, management judgments, accounting estimates, significant
new  accounting  policies  and  disagreements  with  management.  The  Chair may
represent the entire Committee for purposes of this discussion.

  Internal Controls

     15. The Committee  shall discuss with  the outside auditor  and the  senior
internal  audit manager, at  least quarterly, the  adequacy and effectiveness of
the  accounting  and  financial  controls  of  the  Company,  and  consider  any
recommendations for improvement of such internal control procedures.

     16.  The  Committee  shall  discuss  with  the  outside  auditor  and  with
management any  management letter  provided  by the  outside auditor  (or  other
auditor)  and  any other  significant matters  brought to  the attention  of the
Committee by the outside auditor (or other auditor) as a result of its annual or
other audit. The Committee should allow management adequate time to consider any
such matters raised by the outside auditor.

     17. The Committee shall  meet with the  Company's Chief Executive  Officer,
Chief  Financial Officer,  and other  Company management  as appropriate  and as
required by relevant law, including  rules adopted by the  SEC and Nasdaq, on  a
regular   basis  to  discuss  the  Company's  internal  controls  structure  and
procedures and status, and disclosure controls and procedures and status.

  Internal Audit

     18. The Committee shall discuss at least quarterly with the senior internal
audit manager  and  provider  of  internal audit  services  the  activities  and
organizational  structure  of  the  Company's internal  audit  function  and the
qualification of the primary personnel performing such function.

     19. Management shall furnish to the Committee a copy of each internal audit
report.

     20. The Committee shall, at its  discretion, meet with the senior  internal
audit  manager and provider of internal audit services to discuss any reports or
any other  matters brought  to the  attention  of the  Committee by  the  senior
internal audit manager.

     21.  The senior audit manager and provider of internal audit services shall
be granted unfettered access to the Committee.

                                       A-3


  Other Responsibilities

     22. The  Committee shall  review and  reassess the  Committee's charter  at
least  annually  and  submit  any  recommended  changes  to  the  Board  for its
consideration.

     23. The Committee shall provide the  report for inclusion in the  Company's
Annual Proxy Statement required by Item 306 of Regulation S-K of the SEC.

     24.   The  Committee   shall  establish   procedures  in   compliance  with
requirements of relevant law,  including rules adopted by  the SEC, and  Nasdaq,
for  addressing matters and  complaints brought to  the Committee's attention by
employees of the  Company or  other individuals  regarding accounting,  internal
accounting  controls, auditing,  or other  matters, and  shall ensure  that such
complaints brought by  employees are treated  confidentially and anonymously  to
the extent required by law.

     25.  The Committee  shall be responsible  for receiving,  dealing with, and
responding to legal compliance  reports relating to  actual or alleged  material
violations  of the  securities laws, material  breaches of  fiduciary duties, or
similar material violations.

     26. The Committee shall review and approve any related party transaction in
advance of the Company's entering into  any such related party transaction,  and
shall subsequently inform the Board of any such approval.

     27.  The Committee, through its Chair, shall report periodically, as deemed
necessary or desirable by  the Committee, but at  least following its  regularly
scheduled  meetings, to  the full  Board regarding  the Committee's  actions and
recommendations, if any.

                                       A-4


[CABOT MICROELECTRONICS LOGO]

                                                                      APPENDIX B
                          SECOND AMENDED AND RESTATED 2000 EQUITY INCENTIVE PLAN

                          SECOND AMENDED AND RESTATED
         CABOT MICROELECTRONICS CORPORATION 2000 EQUITY INCENTIVE PLAN

1.  PURPOSE

     The purpose  of this  Second Amended  and Restated  Cabot  Microelectronics
Corporation  2000 Equity Incentive Plan (the "Plan") is to advance the interests
of Cabot Microelectronics  Corporation (the "Company")  and its stockholders  by
enhancing  the Company's ability to (a) attract and retain employees, directors,
consultants and advisors who are in a position to make significant contributions
to the success of the Company and its subsidiaries; (b) reward these individuals
for these contributions; (c)  encourage these individuals  to take into  account
the  long-term interests  of the  Company and  its stockholders;  and (d) reward
individuals who have contributed to the Company's success (including the success
of the Company's initial public  offering), in the case  of each of (a)  through
(d),  through ownership of shares of the Company's common stock, par value $.001
per share ("Stock").

2.  ADMINISTRATION

     (a) The Plan  shall be administered  by the Compensation  Committee of  the
Board of Directors (the "Board") of the Company (the "Committee"). The Committee
shall  hold  meetings  at  such  times  as  may  be  necessary  for  the  proper
administration of  the  Plan.  The  Committee shall  consist  of  at  least  two
directors  of the Company,  each of whom  shall be a  "Non-Employee Director" as
defined in  Rule 16b-3(b)(3)  promulgated  under Section  16 of  the  Securities
Exchange  Act  of 1934,  as amended  (the "1934  Act"), and  (ii) to  the extent
necessary for  any Award  intended to  qualify as  "qualified  performance-based
compensation"  under Section  162(m) of  the Internal  Revenue Code  of 1986, as
amended (the "Code"), to so  qualify, each member of  the Committee shall be  an
"outside director" (as defined in Section 162(m) and the regulations promulgated
thereunder). Subject to applicable law, the Committee may delegate its authority
under the Plan to any other person or persons.

     (b)  No member of the Committee shall  be liable for any action, failure to
act, determination or  interpretation made in  good faith with  respect to  this
Plan  or any transaction hereunder. The  Company hereby agrees to indemnify each
member of the Committee for  all costs and expenses  and, to the fullest  extent
permitted by applicable law, any liability incurred in connection with defending
against,  responding to, negotiating for the  settlement of or otherwise dealing
with any claim, cause  of action or  dispute of any  kind arising in  connection
with  any  actions  in administering  this  Plan  or in  authorizing  or denying
authorization to any transaction hereunder.

     (c) Subject  to the  express terms  and conditions  set forth  herein,  the
Committee shall have the power from time to time:

          (i)  to  determine the  Employees, Directors  and/or Advisors  to whom
     Awards shall be granted under  the Plan and the  number of shares of  Stock
     subject  to such Awards; to prescribe  the terms and conditions (which need
     not be  identical)  of  each such  Award;  and  to make  any  amendment  or
     modification to any Award Agreement consistent with the terms of the Plan;

          (ii)  to  construe  and  interpret the  Plan  and  the  Awards granted
     hereunder; to establish,  amend and  revoke rules and  regulations for  the
     administration  of  the Plan,  including,  but not  limited  to, correcting

                                       B-1


     any defect or supplying any  omission, or reconciling any inconsistency  in
     the  Plan or  in any Award  Agreement, in the  manner and to  the extent it
     shall deem necessary  or advisable;  to interpret the  Plan and  applicable
     Award  Agreements so that the Plan  and its operation complies with Section
     16 of  the  1934  Act, Sections  162(m)  and  422 of  the  Code  and  other
     applicable law; and otherwise to give full effect to the Plan;

          (iii) to exercise its discretion with respect to the powers and rights
     granted to it as set forth in the Plan; and

          (iv)  generally, to exercise  such powers and to  perform such acts as
     are deemed by it  necessary or advisable to  promote the best interests  of
     the Company with respect to the Plan.

     All  decisions and determinations  of the Committee in  the exercise of the
foregoing powers shall be final, binding and conclusive upon the Company and its
subsidiaries and  affiliates, all  Employees, Directors  and Advisors,  and  all
other persons claiming any interest herein.

3.  EFFECTIVE DATE AND TERM OF PLAN

     The  Plan will become effective  on the date on which  it is adopted by the
Board, subject  to the  approval of  the Company's  stockholders at  the  Annual
Meeting on March 9, 2004. No Award may be granted under the Plan after the tenth
anniversary  of the date on which this Plan was adopted by the Board, but Awards
previously granted may extend beyond that date.

4.  SHARES SUBJECT TO THE PLAN

     Subject to adjustment as provided in  Section 8.6, and subject to the  next
following  sentence and  Section 6.3(a), the  maximum number of  shares of Stock
that may be delivered under the Plan will be 9,500,000.

     In addition, any Stock covered by  an Option granted under the Plan,  which
is forfeited, cancelled or expires in whole or in part shall be deemed not to be
delivered  for purposes  of determining  the maximum  number of  shares of Stock
available for grants  under the  Plan. Any shares  of Stock  surrendered to  the
Company  in payment of the exercise price of Options issued under the Plan shall
be deemed not to be delivered for purposes of determining the maximum number  of
shares  of  Stock  available  for  grants under  the  Plan.  Upon  forfeiture or
termination of Restricted Stock or Restricted Stock Units prior to vesting,  the
shares  of Stock subject thereto  shall again be available  for Awards under the
Plan.

     In no event  shall the Company  issue ISOs (as  defined in Section  6.2(a))
under the Plan covering more than 1,750,000 shares of Stock.

     Awards  granted through the  assumption of, or  in substitution or exchange
for, similar awards in connection with the acquisition of another corporation or
business entity shall not be counted for purposes of applying the limitations of
this Section on numbers of shares of Stock available for Awards generally or any
particular kind of Award under the Plan.

     Stock delivered under the Plan may  be either from authorized but  unissued
Stock,  from treasury  shares or from  shares of Stock  purchased in open-market
transactions and private sales.

5.  ELIGIBILITY AND PARTICIPATION

     Employees of the  Company, its subsidiaries  and affiliates  ("Employees"),
non-employee  members of the board of directors of the Company, its subsidiaries
or affiliates ("Directors"), and consultants and advisors of the Company or  any
of  its subsidiaries ("Advisors"), who in the  opinion of the Committee are in a
position to make a significant contribution  to the success of the Company,  its
subsidiaries and affiliates, are eligible to receive Awards under the Plan.

     For  purposes of the Plan, "Service" means the provision of services to the
Company or its subsidiaries  or affiliates in the  capacity of (i) an  Employee,
(ii)   a  Director,  or  (iii)  an  Advisor.  An  "affiliate"  for  purposes  of

                                       B-2


the Plan is an entity that controls, is controlled by or is under common control
with, the Company. A "subsidiary" for purposes of the Plan is an entity in which
the Company owns, directly or indirectly, equity interests possessing a majority
of the total combined voting power of all classes of equity. The Committee  will
from  time to time select the Employees, Directors and/or Advisors who are to be
granted Awards ("Participants"), but no  Participant shall receive Awards  under
the  Plan covering more than  300,000 shares of Stock  (subject to adjustment as
provided in Section 8.6) in any calendar year.

6.  TYPES OF AWARDS

     6.1.  RESTRICTED STOCK AND RESTRICTED STOCK UNITS.

     (a)   NATURE  OF RESTRICTED  STOCK  AWARD.  An Award  of  Restricted  Stock
entitles  the recipient to acquire,  at such time or  times as the Committee may
determine, shares of Stock  subject to the  restrictions described in  paragraph
(f) below ("Restricted Stock").

     (b)   RESTRICTED STOCK  UNITS. An Award of  Restricted Stock Units ("RSUs")
entitles the recipient to acquire,  at such time or  times as the Committee  may
determine,  shares of Stock  subject to the  restrictions described in paragraph
(f) below. An RSU represents a contingent right to receive a Share or an  amount
equivalent in value to a Share.

     (c)    MAXIMUM  NUMBER. In  no  event  shall the  Company  issue  more than
1,900,000 shares of Restricted  Stock and/or RSUs, in  the aggregate, under  the
Plan.

     (d)    PAYMENT  FOR  RESTRICTED  STOCK. The  Committee  may  require,  as a
condition to an Award of Restricted Stock or RSUs, that a Participant deliver to
the Company  a purchase  price  in any  amount set  by  the Committee  for  such
Restricted Stock or RSUs. In the discretion of the Committee, an Award Agreement
evidencing  an Award of Restricted  Stock or RSUs may  permit the Participant to
pay some  or all  of the  purchase price  thereof, or  to meet  any  Withholding
Requirements  to be met by the Participant  in connection therewith, in the form
of a note from the Participant on  such terms as the Committee shall  determine.
Such  terms may include  forgiveness of all or  a portion of  any such note upon
such conditions as the Committee may specify.

     (e)   RIGHTS AS  A STOCKHOLDER.  A  Participant who  receives an  Award  of
Restricted  Stock will have all the rights  of a stockholder with respect to the
Stock, including  voting  and  dividend  rights,  subject  to  the  restrictions
described  in  paragraph  (d) below  and  any  other conditions  imposed  by the
Committee in  the Award  Agreement at  the time  of grant.  The Award  Agreement
evidencing an Award of RSUs shall specify whether the Participant is entitled to
any  voting rights or to receive any dividends on the shares of Stock underlying
the RSUs. An  Award of Restricted  Stock or RSUs  may provide for  the right  to
receive  on the payment  date for any  dividend on the  Stock, cash compensation
from the Company equal to the dividend that would have been paid on such  shares
of  Restricted Stock or RSUs (or the Fair Market Value of such dividend, if such
dividend would not have been paid in  cash), if such shares had been issued  and
outstanding,  fully vested and  held by the  Participant on the  record date for
payment of such dividend (a "Dividend Equivalent").

     (f)  RESTRICTIONS. The  restrictions on each grant  of Restricted Stock  or
RSUs  will  lapse  at such  time  or times,  and  on such  terms  and conditions
(including obtaining pre-established  performance goals), as  the Committee  may
specify.  Except  as  otherwise specifically  provided  by  the Plan  or  by the
Committee in  any  particular  case, until  these  restrictions  lapse,  neither
Restricted  Stock  nor  RSUs  may be  sold,  assigned,  transferred,  pledged or
otherwise encumbered or disposed of, except that Restricted Stock or RSUs may be
pledged as security for the  purchase price thereof, or  for loans used to  fund
any  or all  of the  purchase price thereof  or Withholding  Requirements met in
connection with the  purchase thereof. If  the Participant's Service  terminates
before  such  restrictions have  lapsed,  the Company  shall  have the  right to
repurchase the Restricted Stock for  the amount of any consideration  (excluding
services)  it received for the Restricted Stock  plus, if the Committee shall so
determine,  an  amount  equal  to  the  Withholding  Requirements  met  by   the
Participant  in  connection  with the  sale  of  the Stock,  or  for  such other
consideration as the Committee shall  determine, including for no  consideration
if  no consideration other than services was paid for such Restricted Stock. The

                                       B-3


Committee shall not accelerate the time at which the restrictions on all or  any
part  of a  grant of Restricted  Stock will  lapse, except as  the Committee may
determine to be appropriate  in connection with  a Participant's termination  of
Service.

     (g)    DEFERRAL.  If  a  Participant  so  elects  in  accordance  with such
procedures as  the Committee  may specify  from time  to time,  the delivery  of
Restricted  Stock and,  if the deferral  election so specifies,  of the Dividend
Equivalents with respect  thereto, shall  be deferred  until the  date or  dates
specified in such election.

     (h)   SECTION 83(B) ELECTION. Under Section  83 of the Code, the difference
between the purchase  price paid for  the Stock  and its Fair  Market Value  (as
defined  in  Section 6.2(b))  on the  date any  restrictions applicable  to such
shares lapse will be reportable as  ordinary income at that time. A  Participant
may  elect to be taxed at the time the shares of Stock are acquired hereunder to
the extent the Fair Market  Value of the Stock  differs from the purchase  price
rather  than when  and as such  Stock ceases  to be subject  to restrictions, by
filing an election under Section 83(b) of the Code with the I.R.S. within thirty
(30) days after the  grant date. If the  Fair Market Value of  the Stock at  the
grant  date equals  the purchase price  paid (and  thus no tax  is payable), the
election must be made to avoid adverse tax consequences in the future. The  form
for making this election is available from the Company. The failure to make this
filing  within the  thirty (30)  day period  will result  in the  recognition of
ordinary income by the Participant  (in the event the  Fair Market Value of  the
Stock  increases after  the grant  date) as  the restrictions  lapse. IT  IS THE
PARTICIPANT'S SOLE  RESPONSIBILITY, AND  NOT  THE COMPANY'S,  TO FILE  A  TIMELY
ELECTION   UNDER  SECTION  83(b).   A  PARTICIPANT  MUST   RELY  SOLELY  ON  THE
PARTICIPANT'S OWN ADVISORS WITH RESPECT TO THE DECISION AS TO WHETHER OR NOT  TO
FILE AN 83(b) ELECTION.

     6.2.  OPTIONS.

     (a)   NATURE OF OPTIONS.  An Option  is an Award entitling the recipient on
exercise thereof to purchase shares of Stock at a specified exercise price. Both
incentive stock options  (as defined in  Section 422 of  the Code) ("ISOs")  and
Options  that are  not ISOs  may be  granted under  the Plan;  provided that the
Committee may award ISOs only to Employees.

     (b)  EXERCISE PRICE.  The exercise  price of an Option shall be  determined
by  the  Committee and  set forth  in an  applicable Award  Agreement; provided,
however, that the  exercise price  of an  ISO shall not  be less  than the  Fair
Market Value of a share of the Stock on the date the ISO is granted (110% of the
Fair Market Value of a share of Stock on the date of grant in the case of an ISO
granted  to an Employee who owns (within the meaning of Section 422(b)(6) of the
Code) stock possessing more than ten percent of the total combined voting  power
of  all classes of  stock of the Company,  or of a parent  or a subsidiary (such
person, a "Ten Percent Shareholder")). For  purposes of this Plan, "Fair  Market
Value"  on any date means the  closing sales price of the  Stock on such date on
the principal  national securities  exchange on  which the  Stock is  listed  or
admitted  to trading, or, if the Stock is  not so listed or admitted to trading,
the average of the per share closing bid price and per share closing asked price
on such  date  as quoted  on  the  National Association  of  Securities  Dealers
Automated  Quotation  System  or such  other  market  in which  such  prices are
regularly quoted, or, if  there have been no  published bid or asked  quotations
with  respect to shares on  such date, the Fair Market  Value shall be the value
established by the Board in good faith and, in the case of an ISO, in accordance
with Section 422 of the Code. Except for adjustment as provided in Section  8.6,
any outstanding Options shall not be repriced.

     (c)   DURATION  OF OPTIONS.   The  latest date  on which  an Option  may be
exercised will be the tenth anniversary of the date the Option was granted (five
years in the  case of  an ISO  granted to a  Ten Percent  Shareholder), or  such
earlier  date as may have been specified by the Committee in the Award Agreement
at the time the Option was granted.

     (d)  EXERCISE OF OPTIONS.  An  Option will become exercisable at such  time
or  times, and on such terms and conditions (including obtaining pre-established
performance goals), as the Committee may specify in the Award Agreement for such
Option. The Committee may at  any time accelerate the time  at which all or  any
part of the Option may be exercised.
                                       B-4


     Subject  to the next following sentence, any  exercise of an Option must be
in writing, signed by the proper person and delivered or mailed to the  Company,
accompanied  by (1) any documents  required by the Committee  and (2) payment in
full for the number of  shares for which the  Option is exercised. The  exercise
price  for any  Stock purchased pursuant  to the  exercise of an  Option may, if
permitted under the  Award Agreement applicable  to the Option,  be paid in  the
following  forms: (a) cash; (b) the transfer, either actually or by attestation,
to the Company of shares of Stock that have been held by the Participant for  at
least  six months (or such  lesser period as may  be permitted by the Committee)
prior to the exercise  of the Option,  such transfer to be  upon such terms  and
conditions  as  determined  by the  Committee;  (c)  such other  methods  as the
Committee  makes  available  to  Participants  from  time  to  time;  or  (d)  a
combination  thereof. In addition, Options may be exercised through a registered
broker-dealer pursuant to such cashless exercise procedures which are, from time
to time, deemed acceptable by the Committee. Any shares of Stock transferred  to
the  Company as payment of the exercise price under an Option shall be valued at
their Fair Market Value on the day  of exercise of such Option. If requested  by
the  Committee,  the  Participant  shall  deliver  the  Award  Agreement  to the
Secretary of the Company who shall  endorse thereon a notation of such  exercise
and  return such  Award Agreement  to the  Participant. No  fractional shares of
Stock (or cash in lieu thereof) shall be issued upon exercise of an Option,  and
the  number of  shares of  Stock that  may be  purchased upon  exercise shall be
rounded to the nearest number of whole shares.

     (e)  EXERCISE LIMIT.   To the extent that  the aggregate Fair Market  Value
(determined  as of  the date of  the grant) of  shares of Stock  with respect to
which ISOs granted  under the  Plan and  "incentive stock  options" (within  the
meaning of Section 422 of the Code) granted under all other plans of the Company
or  its subsidiaries (in  either case determined without  regard to this Section
6.2(e)) are exercisable by a Participant for the first time during any  calendar
year  exceeds $100,000, such ISOs shall be treated as Options that are not ISOs.
In applying the  limitation in the  preceding sentence in  the case of  multiple
Options,  Options that are intended to be ISOs shall be treated as Options which
are not ISOs according to  the order in which they  were granted, such that  the
most recently granted Options are first treated as Options that are not ISOs.

     (f)   An ISO  must be exercised, if  at all, within  three months after the
Participant's termination of Service for a reason other than death or Disability
and within  twelve months  after the  Participant's termination  of Service  for
death or Disability.

     6.3.  SUBSTITUTE AWARDS.

     (a)    In connection  with any  acquisition by  the Company  or any  of its
subsidiaries, the Committee may  grant Awards to  persons who became  Employees,
Directors  or Advisors in  connection with such  acquisition in substitution for
equity incentives held by them  in the seller or  acquired entity. In such  case
the  Committee may set  the prices and  other terms of  the substitute Awards at
such amounts and in such manner as it, in its sole discretion, deems appropriate
to preserve for the  Participants the economic values  of the equity  incentives
for  which such Awards  are substitutes (as  determined by the  Committee in its
sole discretion) or otherwise  to provide such incentives  as the Committee  may
determine are appropriate.

     (b)    Unless required  by applicable  law,  any substitute  Awards granted
pursuant to Section 6.3 shall not  count toward the share limitations set  forth
in Section 4.

7.  EVENTS AFFECTING OUTSTANDING AWARDS

     7.1.  TERMINATION OF SERVICE.

     Unless   otherwise  set  forth  in  an  Award  Agreement,  an  Award  shall
immediately terminate on the  date a Participant's  Service terminates, and  (i)
any Options held by a Participant shall not be exercisable and all rights of the
Participant with respect thereto shall immediately terminate and (ii) any shares
of  Restricted Stock or  RSU's with respect  to which the  restrictions have not
lapsed shall be immediately forfeited and must be transferred to the Company  in
accordance with Section 6.1.

                                       B-5


     7.2  TERMINATION OF AWARD.

     The  Company may terminate, cancel, rescind or recover an Award immediately
under certain circumstances, including, but not limited to a Participant's:

          (a)   actions  constituting  "Cause", which  shall  have  the  meaning
     provided  under  an employment,  consulting  or other  agreement  between a
     Participant and the Company, or if there is no such meaning provided  under
     such  agreement or no such agreement, shall include, but not be limited to,
     the: (i) conviction of or entering a  guilty plea with respect to a  crime,
     whether  or not connected with  the Company; (ii) commission  of any act of
     fraud  with  respect   to  the  Company;   (iii)  theft,  embezzlement   or
     misappropriation of any property of the Company; (iv) excessive absenteeism
     (other than as resulting from Disability); (v) failure to observe or comply
     with  any Company work rules, policies, procedures, guidelines or standards
     of conduct which the Company has adopted for the regulation of the  general
     conduct  of  its employees,  as  generally known  to  the employees  of the
     Company or  evidenced  by  the  terms of  any  employee  handbook,  written
     memorandums or written policy statements; (vi) continued willful refusal to
     carry  out  and  perform  the material  duties  and  responsibilities  of a
     Participant's position, excluding nonperformance resulting from Disability;
     or (vii) any other conduct or  act determined to be injurious,  detrimental
     or  prejudicial to any interest of the Company, (in each case as determined
     in good faith by the Company.);

          (b)  rendering of  services for a competitor  prior to, or within  six
     (6)  months  after,  the  exercise  of any  Option  or  the  termination of
     Participant's Service with the Company;

          (c)     unauthorized   disclosure  of   any   confidential/proprietary
     information of the Company to any third party;

          (d)    failure to  comply with  the  Company's policies  regarding the
     identification, disclosure and protection of intellectual property; or

          (e)      violation   of   the   Proprietary   Rights   Agreement/Cabot
     Microelectronics   Corporation   Employee   Confidentiality,   Intellectual
     Property  and  Non-Competition  Agreement  for  Employees  signed  by   the
     Participant.

     The  existence of any such circumstances  shall be determined in good faith
by the Company.

     In the event of any termination, cancellation, recision or revocation,  the
Participant shall return to the Company any Stock received pursuant to an Award,
or  pay to the Company the  amount of any gain realized  on the sale of any such
Stock, in such manner and on such  terms and conditions as may be required,  and
the Company shall be entitled to set-off against the amount of any such gain any
amount  owed to the  Participant by the  Company. To the  extent applicable, the
Company will refund to the Participant any amount paid for such Stock, including
Withholding Requirements.

     7.3  CHANGE IN CONTROL.

     The Committee  shall have  the discretion  to provide  in applicable  Award
Agreements  that, in the event of a  "Change in Control" (as defined in Appendix
A) of the Company, the following provisions will apply:

          (a) Each outstanding Option (or such lesser portion of each Option  as
     is  set forth  in an  applicable Award  Agreement) will  immediately become
     exercisable in full.

          (b) Each outstanding share of Restricted Stock or RSU (or such  lesser
     number  of shares as  is set forth  in an applicable  Award Agreement) will
     immediately become free of the restrictions.

          (c) In  the  event  of  a  Change in  Control  that  is  a  merger  or
     consolidation in which the Company is not the surviving corporation or that
     results  in the acquisition of  substantially all the Company's outstanding
     Stock by a single  person or entity  or by a group  of persons or  entities
     acting  in  concert, or  in  the event  of  a sale  or  transfer of  all or
     substantially all of  the Company's assets  (a "Covered Transaction"),  the
     Committee  shall have the discretion to  provide for the termination of all
     outstanding Options as of  the effective date  of the Covered  Transaction;
     provided, that, if the Covered Transaction
                                       B-6


     follows  a Change in Control or would give  rise to a Change in Control, no
     Option will be so terminated (without the consent of the Participant) prior
     to the expiration of 20 days following  the later of (i) the date on  which
     the  Award  became  fully  exercisable  and  (ii)  the  date  on  which the
     Participant received written notice of the Covered Transaction.

8.  GENERAL PROVISIONS

     8.1.  DOCUMENTATION OF AWARDS.

     Awards will be evidenced by written instruments prescribed by the Committee
from time to time (each such instrument, an "Award Agreement"). Award Agreements
may be in the form of agreements, to be executed by both the Participant and the
Company, or certificates,  letters or similar  instruments, acceptance of  which
will evidence agreement to the terms thereof and hereof.

     8.2.  RIGHTS AS A STOCKHOLDER; DIVIDEND EQUIVALENTS.

     Except  as specifically provided by the Plan,  the receipt of an Award will
not give a Participant rights as a stockholder, and the Participant will  obtain
such  rights,  subject to  any  limitations imposed  by  the Plan  or  the Award
Agreement, upon actual  receipt of Stock.  However, the Committee  may, on  such
conditions  as  it  deems appropriate,  provide  in  an Award  Agreement  that a
Participant will receive  a benefit in  lieu of cash  dividends that would  have
been  payable on any  or all Stock  subject to the  Participant's Award had such
Stock been  outstanding.  Without  limitation, the  Committee  may  provide  for
payment  to  the  Participant  of amounts  representing  such  dividends, either
currently or in the future, or for  the investment of such amounts on behalf  of
the Participant.

     8.3  CONDITIONS ON DELIVERY OF STOCK.

     The  Company will not be obligated to  deliver any shares of Stock pursuant
to the  Plan  or to  remove  any restriction  from  shares of  Stock  previously
delivered  under  the Plan  (a)  until all  conditions  of the  Award  have been
satisfied or removed, (b)  until, in the opinion  of the Company's counsel,  all
applicable  federal and state laws and  regulations have been complied with, (c)
if the outstanding Stock is at the time listed on any stock exchange, until  the
shares  to be  delivered have  been listed  or authorized  to be  listed on such
exchange upon official  notice of  notice of issuance  and (d)  until all  other
legal  matters in connection with the issuance  and delivery of such shares have
been approved  by the  Company's counsel.  If the  sale of  Stock has  not  been
registered  under  the  Securities Act  of  1933,  as amended,  the  Company may
require, as  a condition  to  exercise of  the  Award, such  representations  or
agreements  as  counsel  for  the  Company  may  consider  appropriate  to avoid
violation of such  Act and  may require  that the  certificates evidencing  such
Stock bear an appropriate legend restricting transfer.

     8.4.  TAX WITHHOLDING.

     The  Company will withhold  from any payment  made pursuant to  an Award an
amount as may be necessary sufficient to satisfy all minimum federal, state  and
local withholding tax requirements (the "Withholding Requirements").

     The  Committee will have the right to require that the Participant or other
appropriate person remit  to the  Company an  amount sufficient  to satisfy  the
Withholding  Requirements,  or  make  other  arrangements  satisfactory  to  the
Committee with regard to such requirements, prior to the delivery of any  Stock.
If  and to the extent  that any such withholding  is required, the Committee may
permit the Participant or such  other person to elect at  such time and in  such
manner  as the Committee provides to have  the Company hold back from the shares
to be delivered, or to deliver to  the Company, Stock having a value  calculated
to satisfy the Withholding Requirements.

     If  at  the time  an ISO  is  exercised the  Committee determines  that the
Company  could  be  liable  for  Withholding  Requirements  with  respect  to  a
disposition  of the Stock received upon exercise, the Committee may require as a
condition of exercise that the person exercising the ISO agree (a) to inform the
Company

                                       B-7


promptly of any disposition of Stock received upon exercise of the ISO, and  (b)
to  give such  security as  the Committee deems  adequate to  meet the potential
liability of the Company  for the Withholding Requirements  and to augment  such
security  from time  to time  in any amount  reasonably deemed  necessary by the
Committee to preserve the adequacy of such security.

     8.5.  NONTRANSFERABILITY OF AWARDS.

     No Option shall be transferable by a Participant otherwise than by will  or
by  the laws of descent and distribution or, in the case of an Option other than
an ISO,  pursuant to  a domestic  relations order  (within the  meaning of  Rule
16a-12  promulgated under the Exchange Act),  and an Option shall be exercisable
during the  lifetime  of such  Participant  only  by such  Participant  or  such
Participant's  executor or administrator or by the person or persons to whom the
Option is transferred by will or the applicable laws of descent and distribution
(such person,  the Participant's  "Legal Representative").  Notwithstanding  the
foregoing sentence, the Committee may set forth in an Award Agreement evidencing
an  Option (other than an ISO), that the Option may be transferred to members of
the Participant's immediate  family, to trusts  solely for the  benefit of  such
immediate family members and to partnerships in which such family members and/or
trusts  are the only partners, and for  purposes of this Plan, such a transferee
of an Option shall be deemed to be the Participant. For this purpose, "immediate
family" shall  refer  only  to  the  Participant's  spouse,  parents,  children,
stepchildren  and  grandchildren  and  the spouses  of  such  parents, children,
stepchildren and grandchildren. The terms of  an Option shall be final,  binding
and  conclusive  upon the  beneficiaries,  executors, administrators,  heirs and
successors of the Participant.

     8.6.  ADJUSTMENTS IN THE EVENT OF CERTAIN TRANSACTIONS.

     In the  event that  the outstanding  shares of  Stock are  changed into  or
exchanged for a different number or kind of shares of stock, other securities or
other  property of  the Company, an  affiliate or another  legal entity, whether
through merger, consolidation, reorganization, recapitalization, stock dividend,
stock split-up or other substitution of securities of the Company, an  affiliate
or  another  entity, the  Committee shall  make  appropriate adjustments  to the
maximum number and kind of shares of stock or other equity interest as to  which
Awards  may be granted under the Plan and the number and kind of shares of stock
or other equity interest  with respect to which  Awards have been granted  under
the  Plan, the exercise prices for such  shares or other equity interest subject
to Options and any other  economic terms of Awards  granted under the Plan;  and
provided,  that, in the  event of a merger  of the Company  with or into another
entity, any adjustment  provided for  in the  applicable agreement  and plan  of
merger  (or similar document) shall be conclusively deemed to be appropriate for
purposes of this  Section 8.6.  The Committee's  adjustment shall  be final  and
binding for all purposes of the Plan and each Award Agreement entered into under
the  Plan. Unless the Committee otherwise determines, no adjustment provided for
in this Section 8.6 shall require the Company to issue a fractional share,  and,
in  such event, with respect to each  Award Agreement the total adjustment as to
the number of shares  for which Awards  have been granted  shall be effected  by
rounding down to the nearest whole number of shares.

     8.7.  PARTICIPANT'S RIGHTS.

     Neither  the adoption of the Plan nor  the grant of Awards will confer upon
any person any right to continued employment or Service with the Company or  any
subsidiary  or  affiliate or  affect in  any way  the right  of the  Company any
subsidiary or affiliate to  terminate an employment  or Service relationship  at
any time.

     8.8.  PAYMENT FOR STOCK; LOANS.

     Stock awarded under this Plan as Restricted Stock or received upon exercise
of  an Option may be paid for with such legal consideration as the Committee may
determine. If and  to the extent  authorized by the  Committee, the Company  may
permit  Participants to pay for Stock with  promissory notes, and may make loans
to Participants of all or a portion of any Withholding Requirements to be met in
connection with the grant, exercise or vesting of any Award. Any such extensions
of credit may  be secured by  Stock or other  collateral, or may  be made on  an
unsecured basis, as the Committee may determine.

                                       B-8


     8.9.  SUCCESSORS.

     All  obligations of the Company under the  Plan or any Award Agreement will
be binding  on  any successor  to  the Company,  whether  the existence  of  the
successor results from a direct or indirect purchase of all or substantially all
of the Company's shares, or a merger, consolidation, or otherwise.

     8.10.  SEVERABILITY.

     If any provision of the Plan is held illegal or invalid for any reason, the
illegality  or invalidity will not  affect the remaining parts  of the Plan, and
the Plan will be construed and enforced  as if the illegal or invalid  provision
had not been included.

     8.11.  REQUIREMENTS OF LAW.

     The  granting of Awards and the issuance of Share and/or cash payouts under
the Plan will be subject to all applicable laws, rules, and regulations, and  to
any  approvals by governmental agencies or  national securities exchanges as may
be required.

     8.12.  SECURITIES LAW COMPLIANCE.

     As to any individual who is, on the relevant date, an officer, director  or
ten  percent beneficial  owner of any  class of the  Company's equity securities
that is registered pursuant to  Section 12 of the  Exchange Act, all as  defined
under  Section 16 of the Exchange Act, transactions under this Plan are intended
to comply with all applicable conditions  of Rule 16b-3 under the Exchange  Act,
or  any successor rule. To the extent any provision of the Plan or action by the
Board fails  to so  comply, it  will  be deemed  null and  void, to  the  extent
permitted by law and deemed advisable by the Board.

     8.13.  AWARDS TO FOREIGN NATIONALS AND EMPLOYEES OUTSIDE THE UNITED STATES.

     To  the extent  the Board deems  it necessary, appropriate  or desirable to
comply with foreign law or  practice and to further  the purposes of this  Plan,
the  Board may,  without amending  the Plan,  (i) establish  rules applicable to
Awards granted  to  Participants who  are  foreign nationals,  are  employed  or
providing  Service  outside the  United States,  or  both, including  rules that
differ from  those  set forth  in  this Plan,  and  (ii) grant  Awards  to  such
Participants  in accordance with those rules  that would require the application
of the law of any other jurisdiction.

     8.14.  GOVERNING LAW.

     To the extent  not preempted by  federal law, the  Plan and all  agreements
hereunder  will be construed  and enforced in accordance  with, and governed by,
the laws of the  State of Delaware,  without giving effect  to its conflicts  of
laws  principles that  would require  the application  of the  law of  any other
jurisdiction.

9.  PERFORMANCE-BASED RESTRICTED STOCK AWARDS.

     If the Committee makes Restricted Stock or RSU Awards that are designed  to
qualify   for  the  performance-based  exception   from  the  tax  deductibility
limitations of Code Section 162(m)  and any regulations promulgated  thereunder,
the Committee will determine the number of shares awarded and/or vesting of such
Restricted  Stock or  RSU Awards using  performance measures,  which may include
such measures as  financial goals and  business metrics such  as revenue,  gross
margin,  net income, operating  income, earnings per  share, return on operating
assets or  capital,  cash flow  (e.g.,  operating  cash flow,  free  cash  flow,
discounted cash flow return on investment) market share, return to shareholders,
cost  management,  business  growth  through  market  and  technology extension,
safety, improvement in  technology and quality  leadership, business  processes,
organizational  effectiveness and operational excellence  (all e.g., absolute or
peer-group comparative), and/or other performance  measures set by the Board  or
Committee.

     The Committee shall have the discretion to adjust the determinations of the
degree  of attainment  of the  preestablished performance  objectives to reflect
accounting   changes   or   other   events.   In   addition,   in   the    event
                                       B-9


that  the Committee determines that it is advisable to grant Restricted Stock or
RSU Awards  that  may  not  qualify for  the  performance-based  exception,  the
Committee  may  make such  grants without  satisfying  the requirements  of Code
Section 162(m).

10.  DISCONTINUANCE, CANCELLATION, AMENDMENT AND TERMINATION

     The Committee may at any time  discontinue granting Awards under the  Plan.
The  Board may at any time or times amend  the Plan and, with the consent of the
holder thereof, any outstanding Award. The  Committee may at any time  terminate
the Plan as to any further grants of Awards, provided that (except to the extent
expressly required or permitted by the Plan) no such amendment will, without the
approval  of the stockholders of the Company, (a) increase the maximum number of
shares available under the Plan, (b) extend the time within which Awards may  be
granted,  or (c) amend  the provisions of  this Section 10,  and no amendment or
termination of  the Plan  may adversely  affect the  rights of  any  Participant
(without his or her consent) under any Award previously granted.

                                          CABOT MICROELECTRONICS CORPORATION

                                          BY:
                                          --------------------------------------

                                          ITS:
                                          --------------------------------------

                                       B-10


                APPENDIX A TO SECOND AMENDED AND RESTATED CABOT
            MICROELECTRONICS CORPORATION 2000 EQUITY INCENTIVE PLAN

     A "Change in Control" shall be deemed to have occurred if:

          (a)  any "person" as such term is  used in Sections 13(d) and 14(d) of
     the 1934  Act (other  than (i)  the  Company, (ii)  any subsidiary  of  the
     Company,  (iii) any trustee or other  fiduciary holding securities under an
     employee benefit plan of the Company  or of any subsidiary of the  Company,
     or  (iv) any company owned, directly  or indirectly, by the stockholders of
     the Company in  substantially the  same proportions as  their ownership  of
     stock  of the Company), is or becomes the "beneficial owner" (as defined in
     Section 13(d) of the 1934 Act), together with all Affiliates and Associates
     (as such terms are used in Rule 12b-2 of the General Rules and  Regulations
     under  the 1934 Act) of such  person, directly or indirectly, of securities
     of the Company representing  thirty percent (30%) or  more of the  combined
     voting power of the Company's then outstanding securities; or

          (b)  the stockholders of the Company approve a merger or consolidation
     of the  Company  with  any  other  company, other  than  (i)  a  merger  or
     consolidation  which would result  in the voting  securities of the Company
     outstanding immediately prior  thereto continuing to  represent (either  by
     remaining  outstanding or by being converted  into voting securities of the
     surviving entity),  in combination  with the  ownership of  any trustee  or
     other  fiduciary holding securities  under an employee  benefit plan of the
     Company or any subsidiary of the  Company, at least sixty percent (60%)  of
     the  combined voting power of the voting  securities of the Company or such
     surviving entity outstanding immediately after such merger or consolidation
     or (ii) a merger or consolidation effected to implement a  recapitalization
     of  the Company (or similar transaction)  after which no "person" (with the
     method of determining  "beneficial ownership"  used in clause  (a) of  this
     definition)  owns more  than thirty  percent (30%)  of the  combined voting
     power of the  securities of  the Company or  the surviving  entity of  such
     merger or consolidation; or

          (c)  during any  period of  two consecutive  years (not  including any
     period prior  to  the  execution  of the  Plan),  individuals  who  at  the
     beginning  of such period constitute the Board, and any new director (other
     than a director designated  by a person who  has conducted or threatened  a
     proxy  contest, or has entered into an agreement with the Company to effect
     a transaction described in clause (a), (b) or (d) of this definition) whose
     election  by  the  Board  or  nomination  for  election  by  the  Company's
     stockholders  was approved by a  vote of at least  two-thirds ( 2/3) of the
     directors then still in office who  either were directors at the  beginning
     of  the period or whose election  or nomination for election was previously
     so approved cease for any reason to constitute at least a majority thereof;
     or

          (d) the  stockholders  of  the  Company approve  a  plan  of  complete
     liquidation  of the Company or an agreement  for the sale or disposition by
     the Company of all or substantially all of the Company's assets.

                                       B-11


            DETACH HERE IF YOU ARE RETURNING YOUR PROXY CARD BY MAIL
                                                                          ZCBM52

                                     PROXY

                       CABOT MICROELECTRONICS CORPORATION
                 ANNUAL MEETING OF STOCKHOLDERS - MARCH 9, 2004
   THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS OF THE COMPANY

The undersigned stockholder of CABOT MICROELECTRONICS CORPORATION, a Delaware
corporation (the "Company"), hereby appoints William P. Noglows and H. Carol
Bernstein, and each of them, proxies and attorneys-in-fact of the undersigned,
each with full power of substitution, to attend and act for the undersigned at
the Annual Meeting of Stockholders to be held on Tuesday, March 9, 2004 at 8:00
a.m. local time at Cabot Microelectronics Corporation, 870 North Commons Drive,
Aurora, Illinois 60604, and at any adjournments or postponements thereof, and in
connection therewith to vote and represent all of the shares of common stock of
the Company which the undersigned would be entitled to vote.

Each of the above named proxies at said meeting, either in person or by
substitute, shall have and exercise all of the powers of said proxies hereunder.
In their discretion, each of the above-named proxies is authorized to vote upon
such other business incident to the conduct of the Annual Meeting as may
properly come before the meeting or any postponements or adjournments thereof.
The undersigned hereby revokes all prior proxies given by the undersigned to
vote at said meeting.

IF NO INSTRUCTIONS ARE INDICATED HEREIN, THIS PROXY WILL BE TREATED AS A GRANT
OF AUTHORITY TO VOTE FOR THE PROPOSALS AND ANY OTHER MATTERS TO BE VOTED UPON AT
THE ANNUAL MEETING OR AT ANY POSTPONEMENTS OR ADJOURNMENTS THEREOF.

SEE REVERSE       CONTINUED AND TO BE SIGNED ON REVERSE SIDE        SEE REVERSE
   SIDE                                                                SIDE



CABOT MICROELECTRONICS CORPORATION
C/O EQUISERVE TRUST COMPANY N.A.
P.O. BOX 8694
EDISON, NJ 08818-8694



                                                        --------------------

                                                        --------------------

                                          YOUR VOTE IS IMPORTANT. PLEASE VOTE IMMEDIATELY.

       VOTE-BY-INTERNET  [GRAPHIC OF COMPUTER]                                       VOTE-BY-TELEPHONE  [GRAPHIC OF TELEPHONE]
                                                              OR
     LOG ON TO THE INTERNET AND GO TO                                             CALL TOLL-FREE
     HTTP://WWW.EPROXYVOTE.COM/CCMP.                                              1-877-PRX-VOTE (1-877-779-8683)


                                           IF YOU VOTE OVER THE INTERNET OR BY TELEPHONE,
                                                   PLEASE DO NOT MAIL YOUR CARD.

                                      DETACH HERE IF YOU ARE RETURNING YOUR PROXY CARD BY MAIL                               ZCBM51


/X/ PLEASE MARK                                                                                                             | 1995
    VOTES AS IN                                                                                                             |__
    THIS EXAMPLE.


Our board of directors recommends that you vote your shares "FOR" the election of each of the nominees named below under
Proposal 1, "FOR" the ratification of the election of William P. Noglows to the company's board of directors under Proposal 2,
"FOR" the ratification of the selection of PricewaterhouseCoopers LLP as the company's independent auditors for fiscal 2004
under Proposal 3 and "FOR" the Second Amended and Restated 2000 Equity Incentive Plan under Proposal 4.
                                                                                                           FOR  AGAINST  ABSTAIN

1.   Approval of the election to the board of directors of (01)          2.  Ratification of the            / /    / /      / /
     Juan Enriquez-Cabot and (02) H. Laurance Fuller for terms               election of William P.
     expiring in 2007.                                                       Noglows to the company's
                                                                             board of directors for
              FOR BOTH       / /   / /  WITHHOLD                             the term expiring in 2006.
          (EXCEPT AS MARKED             AUTHORITY
          TO THE CONTRARY)              FOR BOTH                         3.  Ratification of the            / /    / /      / /
                                                                             selection of
          / / __________________________________                             PricewaterhouseCoopers LLP
              INSTRUCTION: TO WITHHOLD AUTHORITY                             as the company's independent
              TO VOTE FOR EITHER NOMINEE, MARK                               auditors for fiscal 2004.
              THE BOX ABOVE AND WRITE THAT NOMINEE'S
              NAME IN THE SPACE PROVIDED ABOVE.                          4.  Approval of Second             / /    / /      / /
                                                                             Amended and Restated
                                                                             2000 Equity Incentive
                                                                             Plan.

                                                                          The persons named in this proxy also may vote, in
                                                                          their discretion, upon such other matters as may
                                                                          properly come before the meeting or any postponement
                                                                          or adjournment thereof.

                                                                          MARK HERE FOR ADDRESS CHANGE AND NOTE AT LEFT / /

                                                                          PLEASE COMPLETE, SIGN, AND MAIL THIS PROXY PROMPTLY
                                                                          IN THE ENCLOSED ENVELOPE. NO POSTAGE IS REQUIRED FOR
                                                                          MAILING IN THE UNITED STATES.

                                                                          IMPORTANT: Please date this proxy and sign exactly
                                                                          as your name appears on this proxy. If shares are
                                                                          held by joint tenants, both must sign. When signing
                                                                          as attorney, executor, administrator, trustee or
                                                                          guardian, please give title as such. If a
                                                                          corporation, please sign in full corporate name by
                                                                          president, or authorized officer. If a partnership,
                                                                          please sign in partnership name by authorized
                                                                          person.


Signature: ___________________________________  Date: ___________  Signature: __________________________________  Date: ___________