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                                                                  EXHIBIT 10.9.1

                           ULTRA CLEAN HOLDINGS, INC.
                          EMPLOYEE STOCK PURCHASE PLAN
                        (RESTATED AS OF OCTOBER 21, 2004)

      SECTION 1. Purpose of the Plan.

      The purpose of this Employee Stock Purchase Plan (the "PLAN") is to give
eligible employees of Ultra Clean Holdings, Inc. (the "COMPANY") and its
subsidiaries the ability to share in the Company's future success. The Company
expects that it and its stockholders will benefit from the added interest which
such eligible employees will have in the welfare of the Company as a result of
their increased equity interest in the Company's success. The Plan is intended
to qualify under Section 423 of the Code (as defined below).

      SECTION 2. Definitions.

      The following capitalized terms used in the Plan have the respective
meanings set forth in this Section:

      (a)   "BOARD" means the board of directors of the Company.

      (b)   "CODE" means the Internal Revenue Code of 1986, as amended from time
to time.

      (c)   "COMMITTEE" means a committee of the Board designated by the Board
to administer the Plan. If no committee is so designated by the Board, the full
Board shall be the Committee hereunder.

      (d)   "COMMON STOCK" means the Common Stock, par value $0.001 per share,
of the Company.

      (e)   "COMPENSATION" means base pay prior to any reductions for pre-tax
contributions made to a plan or salary reduction contributions to a plan
excludable from income under Sections 125, 132 or 402(g) of the Code, unless
otherwise determined by the Committee or its delegate. Notwithstanding the
foregoing, unless otherwise determined by the Committee or its delegate,
"Compensation" shall exclude severance pay, bonuses, retirement income, change
in control payments, contingent payments, income derived from stock options,
stock appreciation rights and other equity-based compensation and other forms of
special remuneration.

      (f)   "CORPORATE TRANSACTION" means (i) a merger of the Company with or
into another corporation (other than a merger whose sole purpose is to change
the state of the Company's incorporation or a merger as a result of which the
direct or indirect stockholders of the Company immediately prior to such merger
or consolidation hold, directly or indirectly, less than 50% of the voting power
of the surviving entity); (ii) the

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sale of substantially all of the assets or stock of the Company; or (iii) the
complete liquidation or dissolution of the Company.

      (g)   "ENROLLMENT DATE" means the first date of an Offering Period.

      (h)   "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended, or any successor thereto.

      (i)   "FAIR MARKET VALUE" means, as of any date, the value of Common Stock
determined as follows:

                  (i)   If the Common Stock is listed on any established stock
            exchange or traded on the Nasdaq National Market or the Nasdaq
            SmallCap Market, the Fair Market Value of a share of the Common
            Stock shall be the closing sales price for such stock (or the
            closing bid, if no sales were reported) as quoted on such exchange
            or market (or the exchange or market with the greatest volume of
            trading in the Common Stock) on the last market trading day prior to
            the day of determination, as reported in The Wall Street Journal or
            such other source as the Committee deems reliable.

                  (ii)  In the absence of such markets for the Common Stock, the
            Fair Market Value shall be determined in good faith by the
            Committee.

      (j)   "MAXIMUM SHARE AMOUNT" means, subject to applicable law, the maximum
number of Shares that a Participant may purchase on any given Purchase Date, as
determined by the Committee in its sole discretion.

      (k)   "NEW PURCHASE DATE" means the purchase date established pursuant to
Section 12 of the Plan.

      (l)   "OFFERING PERIOD" means a period of approximately 12 months
consisting of consecutive Purchase Periods (or such other period as may be
determined by the Committee), as set forth in Section 7.

      (m)   "OPTION" means an option granted pursuant to Section 7 of the Plan.

      (n)   "PARTICIPANT" means an eligible employee of the Company or a
Participating Subsidiary who participates in the Plan.

      (o)   "PARTICIPATING SUBSIDIARY" means a Subsidiary that is selected to
participate in the Plan by the Committee in its sole discretion.

      (p)   "PAYROLL DEDUCTION ACCOUNT" means an account to which payroll
deductions of a Participant are credited under Section 8(c) of the Plan.

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      (q)   "PERSON" means an individual, corporation, partnership, limited
partnership, syndicate, person (including, without limitation, a "person" as
defined in Section 13(d)(3) of the Exchange Act), trust, association or entity
or government, political subdivision, agency or instrumentality of a government,
but excluding any of the Company, any Subsidiary or any employee benefit plan
sponsored or maintained by the Company or any Subsidiary.

      (r)   "PURCHASE DATE" means the last trading day of a Purchase Period.

      (s)   "PURCHASE PERIOD" means the approximately six-month period
commencing after one Purchase Date and ending with the next Purchase Date,
except that the first Purchase Period of any Offering Period will commence on
the applicable Enrollment Date.

      (t)   "PURCHASE PRICE" means, with respect to each Share, 85% of the
lesser of (i) the Fair Market Value of a Share on the Enrollment Date and (ii)
the Fair Market Value of a Share on the Purchase Date, or such other purchase
price as may be determined by the Committee.

      (u)   "SHARE" means a share of Common Stock of the Company.

      (v)   "SUBSIDIARY" means any corporation, partnership, joint venture or
other legal entity of which the Company owns directly or indirectly, more than
50% of the total combined voting power of all classes of stock or other equity
interests of such entity.

      SECTION 3. Shares Subject To The Plan.

      The total number of Shares subject to the Plan is 555,343. The Shares will
consist in whole or in part of authorized but unissued Shares or treasury
Shares, including Shares purchased on the open market or otherwise.

      SECTION 4. Administration.

      (a)   The Plan shall be administered by the Committee. Subject to the
terms of the Plan and applicable law, the Committee shall have full power and
authority to: (i) designate Participants; (ii) interpret and administer the
Plan; (iii) establish, amend, suspend or waive such rules and regulations and
appoint such agents as it shall deem appropriate for the proper administration
of the Plan; (iv) correct any defect or supply any omission or reconcile any
inconsistency in the Plan in the manner and to the extent the Committee deems
necessary or desirable; and (v) make any other determination and take any other
action that the Committee deems necessary or desirable for the administration of
the Plan.

      (b)   All decisions of the Committee shall be final, conclusive and
binding upon all persons.

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      SECTION 5. Eligibility.

      Any individual who is employed by the Company or a Participating
Subsidiary on a given Enrollment Date is eligible to participate in the Plan,
subject to limitations imposed by Section 423 of the Code or as otherwise
determined by the Committee. Notwithstanding the foregoing, no Employee shall be
granted an option under the Plan if, immediately after the grant, such Employee
(or any other person whose stock would be attributed to such Employee pursuant
to Section 424(d) of the Code) would own stock possessing 5% or more of the
total combined voting power or value of all classes of stock of the Company or
its Subsidiaries.

      SECTION 6. Election to Participate.

      Pursuant to procedures set forth by the Committee, Participants may elect
to participate in a given Offering Period under the Plan prior to the Enrollment
Date for such Offering Period. Enrollments shall remain in effect for subsequent
Offering Periods, except as provided herein. A Participant shall not be enrolled
in more than one Offering Period at any time.

      SECTION 7. Offering Periods; Grant of Option on Enrollment; Purchase of
Shares.

      (a)   The Plan shall be implemented by consecutive, overlapping Offering
Periods with a new Offering Period commencing on a date determined by the
Committee. The first Offering Period and Purchase Period shall begin on June 14,
2004 and end on November 19, 2004. The next Offering Period and Purchase Period
shall begin on November 20, 2004 and end on May 19, 2005. The timing of any
subsequent Offering Periods and Purchase Periods shall be determined by the
Committee.

      (b)   With respect to an Offering Period, each Participant enrolled in
such Offering Period shall be granted as of the Enrollment Date an Option to
purchase on each Purchase Date during the Offering Period a number of Shares
equal to the lesser of (i) the Maximum Share Amount, (ii) $25,000 divided by the
Fair Market Value of the Common Stock on the Enrollment Date, or (iii) the
number determined by dividing (A) the amount accumulated in such Participant's
Payroll Deduction Account as of the Purchase Date by (B) the Purchase Price.

      (c)   In the event that the Committee determines that the number of Shares
that may be purchased on a Purchase Date may exceed the number of Shares
available under Section 3, the Committee may in its discretion provide for a pro
rata purchase on the Purchase Date, and may continue or terminate any Offering
Periods then in effect.

      SECTION 8. Payment of Purchase Price; Changes in Payroll Deductions;
Issuance of Shares.

      (a)   Payroll deductions shall be made on each day that a Participant is
paid during an Offering Period in respect of a payroll period with a payment
date commencing after the Enrollment Date. The deductions shall be made as a
percentage of the

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Participant's Compensation in 1% increments, from 1% to 10% of such
Participant's Compensation, as elected by the Participant; provided that, in
accordance with Section 423(b)(8) of the Code, no Participant shall be permitted
to accrue rights to purchase Shares under this Plan (and any other employee
stock purchase plan of the Company or any of its Subsidiaries) with an aggregate
Fair Market Value (as determined as of the date the applicable option is
granted) in excess of $25,000 for each calendar year in which such option is
outstanding at any time.

      (b)   A Participant may discontinue his or her participation in the Plan
as provided in Section 9, or may change the rate of his or her payroll
deductions during an Offering Period by completing and filing with the Company a
new authorization for payroll deduction, subject to clause (a) above. The
Committee may, in its discretion, limit the number of participation rate changes
in any Offering Period. The change in rate shall be effective as soon as
administratively feasible following the Company's receipt of the new
authorization.

      (c)   All payroll deductions made with respect to a Participant shall be
credited to the Participant's Payroll Deduction Account under the Plan and shall
be deposited with the general funds of the Company, and no interest shall accrue
on the amounts credited to such Payroll Deduction Account, in either case except
as otherwise required by law or as determined by the Committee. All payroll
deductions received or held by the Company may be used by the Company for any
corporate purpose and the Company shall not be obligated to segregate such
payroll deductions, except as otherwise required by law or as determined by the
Committee. Except to the extent provided by the Committee, a Participant may not
make any separate cash payments into such Participant's Payroll Deduction
Account, and payment for Shares purchased under the Plan may not be made in any
form other than by payroll deduction.

      (d)   On each Purchase Date, all funds then in the Participant's Payroll
Deduction Account shall be applied to purchase Shares (or fractions thereof)
pursuant to the automatic exercise of the Option granted on the Enrollment Date.
The Committee may determine with respect to all Participants that any fractional
shares shall be rounded down to the next lower whole share, in which event the
resulting unused amount in any Participant's Payroll Deduction Account may be
carried over into the next Purchase Period.

      (e)   Certificates representing the Shares purchased by a Participant
under the Plan shall be issued to the Participant as soon as practicable
following the end of each Purchase Period, except that the Committee may
determine that such Shares shall be held for each Participant's benefit by a
broker designated by the Committee.

      (f)   The Participant shall have no interest or voting right in the Shares
covered by the Participant's Option until such Option is exercised and the
covered Shares are registered in the name of the Participant.

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      SECTION 9. Withdrawal.

      Each Participant may withdraw from participation prior to the end of an
Offering Period or from the Plan in accordance with procedures set forth by the
Committee. Upon a Participant's withdrawal from participation in respect of any
Offering Period or from the Plan, all accumulated payroll deductions in the
Payroll Deduction Account shall be returned, without interest, to such
Participant (except as otherwise required by law or as determined by the
Committee), and such Participant shall not be entitled to any Shares on the
Purchase Date or thereafter with respect to the Offering Period in effect at the
time of such withdrawal. If a Participant withdraws from an Offering Period,
payroll deductions will not resume at the beginning of the succeeding Offering
Period unless the Participant re-enrolls in the Plan in accordance with
procedures set forth by the Committee prior to the applicable Enrollment Date.

      SECTION 10. Termination of Employment.

      A Participant shall cease to participate in the Plan upon the
Participant's termination of employment for any reason (including death), and
all accumulated payroll deductions in the Payroll Deduction Account shall be
returned, without interest, to such Participant. For purposes of the Plan,
transfers from the Company or a Participating Subsidiary to another
Participating Subsidiary or to the Company, as the case may be, shall not be a
termination of employment. Employment shall not be deemed to terminate when the
Participant goes on a leave of absence approved by the Company in writing,
unless otherwise required by the Code and the applicable regulations.

      SECTION 11. Automatic Transfer to Low Price Offering Period.

      To the extent permitted by any applicable laws and regulations, if the
Fair Market Value of the Shares on any Purchase Date in an Offering Period is
lower than the Fair Market Value of the Shares on the Enrollment Date of such
Offering Period, then all Participants in such Offering Period shall be
automatically withdrawn from such Offering Period immediately after the purchase
of their Shares on such Purchase Date and automatically re-enrolled in a new
Offering Period as of the first business day after such Purchase Date.

      SECTION 12. Adjustments Upon Certain Events.

      Notwithstanding any other provisions in the Plan to the contrary, the
following provisions shall apply to all Options granted under the Plan:

      (a)   In the event of any stock split, reverse stock split, stock
dividend, combination or reclassification of the Common Stock, or any other
increase or decrease in the number of issued shares of Common Stock effected
without receipt of consideration by the Company, the Committee shall, in such
manner as it may deem equitable, adjust any or all of (i) the number or type of
Shares or other securities issued or reserved for issuance pursuant to the Plan,
(ii) the Purchase Price and/or (iii) any other affected terms hereunder.

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      (b)   In the event of a Corporate Transaction, unless each outstanding
Option shall be continued or assumed or an equivalent option substituted by the
Company or the successor corporation or a parent or Subsidiary of the successor
corporation, the Committee shall shorten any Offering Period then in progress by
setting a New Purchase Date, which shall be before the date of the consummation
of the Corporate Transaction. The Committee shall notify each Participant not
less than 10 days prior to the New Purchase Date that (i) a New Purchase Date
has been set and (ii) the Participant's Option will be exercised automatically
on the New Purchase Date unless prior to such date the Participant has withdrawn
from the Offering Period as provided in Section 9. Each Offering Period then in
effect shall terminate on such New Purchase Date.

      SECTION 13. Nontransferability.

      Unless otherwise determined by the Committee, Options granted under the
Plan shall not be transferable or assignable by the Participant other than by
will or by the laws of descent and distribution.

      SECTION 14. Legal Compliance.

      Shares shall not be issued hereunder unless the issuance and delivery of
such Shares shall comply with all applicable laws and regulations, including the
federal and state securities laws and the regulations of any stock exchange or
other securities market on which the Company's securities are traded.

      SECTION 15. No Right to Employment.

      The granting of an Option under the Plan shall impose no obligation on the
Company or any Subsidiary to continue the employment of a Participant and shall
not lessen or affect the Company's or Subsidiary's right to terminate the
employment of such Participant.

      SECTION 16. Amendment or Termination of the Plan.

      (a)   The Plan shall continue until the earliest to occur of the
following: (i) termination of the Plan by the Board, (ii) issuance of all of the
Shares reserved for issuance under the Plan or (iii) the twentieth anniversary
of the effective date of the Plan.

      (b)   The Committee may amend, alter or discontinue the Plan or any
portion thereof at any time, provided that no amendment, alteration or
discontinuation shall be made (x) without the approval of the stockholders of
the Company if such amendment, alteration or discontinuation would (except as is
provided in Section 12) increase the total number of Shares reserved for
purposes of the Plan or as otherwise required by applicable laws or regulations,
or (y) without the consent of a Participant if such amendment, alteration or
discontinuation would materially diminish any of the rights or obligations under
any Option theretofore granted to such Participant under the Plan (except as
otherwise provided in this Section 16).

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      (c)   Notwithstanding clause (y) of Section 16(b), the Committee may amend
or terminate the Plan, including with respect to any Offering Periods then in
effect, without consent of the Participants in such manner as it deems necessary
to permit the granting of Options meeting the requirements of the Code or other
applicable laws or in the event the Board determines that the ongoing operation
of the Plan may result in unfavorable financial accounting consequences for the
Company.

      (d)   Notwithstanding clause (y) of Section 16(b), the Committee shall
have the power at any time to change the duration and timing of current and
future Offering Periods and Purchase Periods; provided that in no event shall
any such Offering Period be longer than 27 months.

      SECTION 17. Taxes.

      At the time the Shares are purchased, or at the time some or all of the
Shares issued under the Plan are disposed of, the Participant must make adequate
provision for the Company's federal, state or other tax withholding obligations,
if any, which arise. At any time, the Company, may, but shall not be obligated
to, withhold from the Participant's compensation the amount necessary for the
Company to meet applicable withholding obligations, including any withholding
required to make available to the Company any tax deductions or benefits
attributable to sale or early disposition of Shares by the Participant.

      SECTION 18. Governing Law.

      The Plan shall be governed by and construed in accordance with the laws of
the State of Delaware, without regard to conflicts of laws.

      SECTION 19. Effectiveness of the Plan.

      The Plan shall become effective as determined by the Board, subject to
stockholder approval as required by law or applicable tax regulations.

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