Exhibit 10.46

Non-Employee Directors’ Compensation Summary as of March 5, 2007

Effective as of March 5, 2007, non-employee directors are eligible for the
following compensation:

 Annual Retainer Fee
 $35,000
   Meeting Fees
  $1,500
  per meeting   Committee Chair Annual Retainer Fees:           Audit Committee
Chairperson
  $20,000
        Compensation Committee Chairperson
  $10,000
        Nominating and Corporate Governance Chairperson
  $10,000
   Annual Non-qualified Stock Option Grant *
 6,000
  options  Annual Restricted Stock Award *
   2,000
  shares  Initial Non-qualified Stock Option Grant **
   7,500
  options  Initial Restricted Stock Award **
 2,500
  shares

                 

 *
 Vesting occurs 25% per year over a four-year period, with first vesting on the
anniversary of the grant/award date
 **
 Vesting occurs 25% immediately on the grant/award date, and 25% per year on the
next three anniversaries of the grant/award date

Under our Directors’ Cash Compensation Umbrella Program (previously filed as
Exhibit 10.36), non-employee directors continue to be eligible to choose to
receive annual retainer fees, committee chair annual retainer fees and meeting
fees either in cash, in fully vested restricted stock under the Second Amended
and Restated Cabot Microelectronics Corporation 2000 Equity Incentive Plan, as
amended and restated September 26, 2006 (previously filed as Exhibit 10.1) or as
deferred compensation under the Company’s Directors’ Deferred Compensation Plan,
as amended September 26, 2006 (“Directors’ Deferred Compensation Plan”). The
Directors’ Deferred Compensation Plan, which was previously filed as Exhibit
10.28, allows non-employee directors to defer their compensation in the form of
rights to acquire the equivalent number of shares of common stock at the end of
the deferral period. Non-employee directors continue to receive their respective
annual retainer fees, committee chair annual retainer fees, annual non-qualified
stock option grants and annual restricted stock awards at the time of the
Company’s annual meeting. Non-employee directors receive their initial
non-qualified stock option grant and restricted stock award, as well as their
first annual non-qualified stock option grant and restricted stock award, upon
the date of the director’s election to the Board of Directors, if other than the
annual meeting date.
.