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                                                                     EXHIBIT 4.2


                          ON SEMICONDUCTOR CORPORATION
                   (FORMERLY KNOWN AS SCG HOLDING CORPORATION)

                        2000 EMPLOYEE STOCK PURCHASE PLAN
           (AS ADOPTED BY THE BOARD OF DIRECTORS ON FEBRUARY 17, 2000;
                      AMENDED AND RESTATED APRIL 21, 2000;
                       AMENDED AND RESTATED MAY 23, 2001)

      1.    PURPOSE. The purpose of this SCG Holding Corporation 2000 Employee
Stock Purchase Plan (the "Plan") is to encourage stock ownership by eligible
employees of SCG Holding Corporation (the "Company") and its Subsidiaries and
thereby provide employees with an incentive to contribute to the profitability
and success of the Company. The Plan is intended to qualify as an "employee
stock purchase plan" under Section 423 of the Code and will be maintained for
the exclusive benefit of eligible employees of the Company and its Subsidiaries.

      2.    DEFINITIONS. For purposes of the Plan, in addition to the terms
defined in Section 1, the following terms are defined:

            (a)   "Board" means the Board of Directors of the Company.

            (b)   "Cash Account" means the account maintained on behalf of a
Participant by the Company for the purpose of holding cash contributions
withheld from payroll pending investment in Stock.

            (c)   "Code" means the Internal Revenue Code of 1986, as amended.

            (d)   "Custodian" means Solomon Smith Barney or any successor or
replacement appointed by the Board or its delagatee under Section 3(a).

            (e)   "Earnings" means a Participant's salary or wages, including
bonuses, for services performed for the Company and its Subsidiaries and
received by a Participant for services rendered during an Offering Period.

            (f)   "Fair Market Value" means the closing price of the Stock on
the relevant date as reported on NASDAQ (or any national securities exchange or
quotation system on which the Stock is then listed), or if there were no sales
on that date the closing price on the next preceding date for which a closing
price was reported; provided, however, that for any Offering Period beginning on
the IPO Date, the Fair Market Value of the Stock on the first day of such
Offering Period shall be deemed to be the price at which the Company's Stock is
offered under its initial public offering of Stock.

            (g)   "IPO Date" means the date on which the Company's initial
public offering of Stock is consummated.

            (h)   "Offering Period" means the period beginning on the IPO Date
and ending on the last day of the next calendar quarter, and every three-month
period thereafter. For


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Participants who do not reside in the United States, if the day on which the
Company receives approval by the applicable foreign jurisdiction to offer common
stock to Participants residing in that jurisdiction is later than the day on
which the Company's initial public offering becomes effective, the Offering
Period means the period beginning on the day on which the Company receives
approval by the applicable foreign jurisdiction to offer common stock to such
Participants and ending on the last day of the next calendar quarter, and every
three-month period thereafter.

            (i)   "Participant" means an employee of the Company or a Subsidiary
who is participating in the Plan.

            (j)   "Purchase Right" means a Participant's option to purchase
Stock that is deemed to be outstanding during an Offering Period. A Purchase
Right represents an "option" under Section 423 of the Code.

            (k)   "Stock" means the common stock of the Company.

            (l)   "Stock Account" means the account maintained on behalf of the
Participant by the Custodian for the purpose of holding Stock acquired under the
Plan.

            (m)   "Subsidiary" means any corporation (other than the Company) in
an unbroken chain of corporations beginning with the Company if each of the
corporations (other than the last corporation in the unbroken chain) owns stock
possessing 50% or more of the total combined voting power of all classes of
stock in one of the other corporations in the chain as set forth in Code Section
424(f).

      3.    ADMINISTRATION.

            (a)   Board Administration. The Plan will be administered by the
Board. The Board may delegate its administrative duties and authority (other
than its authority to amend the Plan) to any Board committee or to any officers
or employees or committee thereof as the Board may designate (in which case
references to the Board will be deemed to refer to the administrator to which
such duties and authority have been delegated). The Board will have full
authority to adopt, amend, suspend, waive, and rescind rules and regulations and
appoint agents as it deems necessary or advisable to administer the Plan, to
correct any defect or supply any omission or reconcile any inconsistency in the
Plan and to construe and interpret the Plan and rules and regulations
thereunder, to furnish to the Custodian such information as the Custodian may
require, and to make all other decisions and determinations under the Plan
(including determinations relating to eligibility). No person acting in
connection with the administration of the Plan will, in that capacity,
participate in deciding any matter relating to his or her participation in the
Plan.

            (b)   The Custodian. The Custodian will act as custodian under the
Plan, and will perform duties under the Plan and in any agreement between the
Company and the Custodian. The Custodian will establish and maintain
Participants Stock Accounts and any subaccounts as may be necessary or desirable
to administer the Plan.



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            (c)   Waivers. The Board may waive or modify any requirement that a
notice or election be made or filed under the Plan a specified period in advance
on an individual case or by adopting a rule or regulation under the Plan,
without amending the Plan.

            (d)   Other Administrative Provisions. The Company will furnish
information from its records as directed by the Board, and such records,
including a Participant's Earnings, will be conclusive on all persons unless
determined by the Board to be incorrect. Each Participant and other person
claiming benefits under the Plan must furnish to the Company in writing an
up-to-date mailing address and any other information as the Board or Custodian
may reasonably request. Any communication, statement, or notice mailed with
postage prepaid to any such Participant or other person at the last mailing
address filed with the Company will be deemed sufficiently given when mailed and
will be binding upon the named recipient. The Plan will be administered on a
reasonable and nondiscriminatory basis and uniform rules will apply to all
persons similarly situated. All Participants will have equal rights and
privileges (subject to the terms of the Plan) with respect to Purchase Right
outstanding during any given Offering Period in accordance with Code Section
423(b)(5).

      4.    STOCK SUBJECT TO PLAN. Subject to adjustment as provided below, the
total number of shares of Stock reserved and available for issuance or which may
be otherwise acquired upon exercise of Purchase Rights under the Plan will be
5,500,000. If, at the end of any Offering Period, the number of shares of Stock
with respect to which Purchase Rights are to be exercised exceeds the number of
shares of Stock then available under the Plan, the Board shall make a pro rata
allocation of the shares of Stock remaining available for purchase in as uniform
a manner as shall be practicable and as it shall determine to be equitable. Any
shares of Stock delivered by the Company under the Plan may consist, in whole or
in part, of authorized and unissued shares or treasury shares or shares of Stock
purchased on the open market. The number and kind of such shares of Stock
subject to the Plan will be proportionately adjusted, as determined by the
Board, in the event of any extraordinary dividend or other distribution,
recapitalization, forward or reverse split, reorganization, merger,
consolidation, spin-off, combination, repurchase, or share exchange, or other
similar corporate transaction or event affecting the Stock.

      5.    ENROLLMENT AND CONTRIBUTIONS.

            (a)   Eligibility. An employee of the Company or any Subsidiary
designated by the Board may be enrolled in the Plan for any Offering Period if
such employee is employed by the Company or a Subsidiary authorized to
participate in the Plan on the first day of the Offering Period, unless one of
the following applies to the employee:

                  (i)   such person has been employed by the Company or a
                        Subsidiary less than 90 days; or

                  (ii)  such person is customarily employed by the Company or a
                        Subsidiary for 20 hours or less a week; or



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                  (iii) such person is customarily employed by the Company or a
                        Subsidiary for not more than five months in any calendar
                        year;

                  (iv)  such person would, immediately upon enrollment, be
                        deemed to own, for purposes of Section 423(b)(3) of the
                        Code, an aggregate of five percent or more of the total
                        combined voting power or value of all outstanding shares
                        of all classes of the Stock of the Company or any
                        Subsidiary.

            Notwithstanding the above, solely for purposes of the first Offering
Period under the Plan, an employee who is employed by the Company or a
Subsidiary on the first day of such Offering Period and who is otherwise
eligible to participate in the Plan shall not be required to satisfy the 90 day
employment period specified in 5(a)(i) above.

            The Company will notify an employee of the date as of which he or
she is eligible to enroll in the Plan, and will make available to each eligible
employee the necessary enrollment forms. Notwithstanding the above, any
individual who is employed by the Company or a Subsidiary designated by the
Board and who is working outside of the United States shall not be eligible to
participate in the Plan if the laws of the country in which the employee is
working makes the offer of the Purchase Right or the delivery of Stock under the
Plan impractical. Additionally, the offer of the Purchase Right and the delivery
of Stock under the Plan shall be effective for any individual who is employed by
the Company or a Subsidiary and who is working outside of the United States only
after the Company has complied with the applicable laws of the country in which
the employee is working.

            (b)   Initial Enrollment. An employee who is eligible under Section
5(a) (or who will become eligible on or before a given Offering Period) may,
after receiving current information about the Plan, initially enroll in the Plan
by executing and filing with the Company a properly completed enrollment form,
including the employee's election as to the rate of payroll contributions for
the Offering Period. To be effective for any Offering Period, such enrollment
form must be filed at least two weeks (or such other period determined by the
Board) preceding such Offering Period.

            (c)   Automatic Re-enrollment for Subsequent Offering Periods. A
Participant whose enrollment in, and payroll contributions under, the Plan
continues throughout a Offering Period will automatically be re-enrolled in the
Plan for the next Offering Period unless (i) the Participant terminates
enrollment before the next Offering Period in accordance with Section 7(a), or
(ii) the Participant is ineligible to participate under Section 5(a). The
initial rate of payroll contributions for a Participant who is automatically
re-enrolled for a Offering Period will be the same as the rate of payroll
contribution in effect at the end of the preceding Offering Period, unless the
Participant files a new enrollment form designating a different rate of payroll
contributions and such new enrollment form is received no later than two weeks
(or such other period determined by the Board) prior to the beginning of the
next Offering Period.

            (d)   Payroll Contributions. A Participant will make contributions
under the Plan by means of payroll deductions from each payroll period which
ends during the Offering Period,


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at the rate elected by the Participant in his or her enrollment form in effect
for that Offering Period (except that such rate may be changed during the
Offering Period to the extent permitted below). The rate of payroll
contributions elected by a Participant may not be less than one percent (1%) nor
more than ten percent (10%) of the Participant's Earnings for each payroll
period, and only whole percentages may be elected; provided, however, that the
Board may specify a lower minimum rate and higher maximum rate, subject to
Section 8(c). Notwithstanding the above, a Participant's payroll contributions
will be adjusted downward by the Company as necessary to ensure that the limit
on the amount of Stock purchased for an Offering Period set forth in Section
6(a)(iii) is not exceeded. A Participant may elect to increase, decrease, or
discontinue payroll contributions for a future Offering Period by filing a new
enrollment form designating a different rate of payroll contributions, which
form must be received at least two weeks (or such other period determined by the
Board) prior to the beginning of an Offering Period to be effective for that
Offering Period. In addition, a Participant may elect to discontinue payroll
contributions during an Offering Period by filing a new enrollment form, such
change to be effective for the next payroll after the Participant's new
enrollment form is received.

            (e)   Crediting Payroll Contributions to Cash Accounts. All payroll
contributions by a Participant under the Plan will be credited to a Cash Account
maintained by the Company on behalf of the Participant. The Company will credit
payroll contributions to each Participant's Cash Account as soon as practicable
after the contributions are withheld from the Participant's Earnings.

            (f)   No Interest on Cash Accounts. No interest will be credited or
paid on cash balances in Participant's Cash Accounts pending investment in
Stock.

      6.    PURCHASES OF STOCK

            (a)   Purchase Rights. Enrollment in the Plan for any Offering
Period by a Participant will constitute a grant by the Company of a Purchase
Right to such Participant for such Offering Period. Each Purchase Right will be
subject to the following terms:

                  (i)   The purchase price of each share of Stock purchased for
                        each Offering Period will equal 85% of the lesser of the
                        Fair Market Value of a share of Stock on the first day
                        of an Offering Period, or the Fair Market Value of a
                        share of Stock on the last day of an Offering Period.

                  (ii)  Except as limited in (iii) below, the number of shares
                        of Stock that may be purchased upon exercise of the
                        Purchase Right for a Offering Period will equal the
                        number of shares (including fractional shares) that can
                        be purchased at the purchase price specified in Section
                        6(a)(i) with the aggregate amount credited to the
                        Participant's Cash Account as of the last day of an
                        Offering Period.



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                  (iii) The number of shares of Stock subject to a Participant's
                        Purchase Right for any Offering Period will not exceed
                        the lesser of: (1) 500 shares of Stock, or (2) the
                        number derived by dividing $6,250 by 100% of the Fair
                        Market Value of one share of Stock on the first day of
                        the Offering Period for the Offering Period.

                  (iv)  The Purchase Right will be automatically exercised on
                        the last day of the Offering Period.

                  (v)   Payments by a Participant for Stock purchased under a
                        Purchase Right will be made only through payroll
                        deduction in accordance with Section 5(d) and (e).

                  (vi)  The Purchase Right will expire on the earlier of the
                        last day of the Offering Period or the date on which the
                        Participant's enrollment in the Plan terminates.

            (b)   Purchase of Stock. At or as promptly as practicable after the
last day of an Offering Period, amounts credited to each Participant's Cash
Account will be applied by the Company to purchase Stock, in accordance with the
terms of the Plan. Shares of Stock will be purchased from the Company or in the
open market, as the Board determines. The Company will aggregate the amounts in
all Cash Accounts when purchasing Stock, and shares purchased will be allocated
to each Participant's Stock Account in proportion to the cash amounts withdrawn
from such Participant's Cash Account. After completing purchases for each
Offering Period (which will be completed in not more than 15 calendar days after
the last day of an Offering Period), all shares of Stock so purchased for a
Participant will be credited to the Participant's Stock Account.

            (c)   Dividend Reinvestment; Other Distributions. Cash dividends on
any Stock credited to a Participant's Stock Account will be automatically
reinvested in additional shares of Stock; such amounts will not be available in
the form of cash to Participants. The Company will aggregate all purchases of
Stock in connection with dividend reinvestment for a given dividend payment
date. Purchases of Stock for purposes of dividend reinvestment will be made as
promptly as practicable (but not more than 15 calendar days) after a dividend
payment date. The purchases will be made directly from the Company at 100% of
the Fair Market Value of a share of Stock on the dividend payment date or on the
open market. Any shares of Stock distributed as a dividend or distribution in
respect of shares of Stock or in connection with a split of the Stock credited
to a Participant's Stock Account will be credited to such Account.

            (d)   Withdrawals and Transfers. Shares of Stock may be withdrawn
from a Participant's Stock Account, in which case one or more certificates for
whole shares may be issued in the name of, and delivered to, the Participant,
with such Participant receiving cash in lieu of fractional shares based on the
Fair Market Value of a share of Stock on the day preceding the date of
withdrawal. Alternatively, whole shares of Stock may be withdrawn from a
Participant's Stock Account by means of a transfer to a broker-dealer or
financial institution that maintains an account for the Participant, together
with the transfer of cash in lieu of fractional



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shares based on the Fair Market Value of a share of Stock on the day preceding
the date of withdrawal. Participants may not designate any other person to
receive shares of Stock withdrawn or transferred under the Plan. A Participant
seeking to withdraw or transfer shares of Stock must give instructions to the
Custodian in such manner and form as may be prescribed by the Custodian, which
instructions will be acted upon as promptly as practicable. Withdrawals and
transfers will be subject to any fees imposed in accordance with Section 8(a).

            (e)   Excess Account Balances. If any amounts remain in a Cash
Account following the date on which the Company purchases Stock for an Offering
Period as a result of the limitation set forth in Section 6(a)(iii) or for any
other reason, such amounts will be returned to the Participant as promptly as
practicable.

      7.    TERMINATION AND DISTRIBUTIONS.

            (a)   Termination of Enrollment. A Participant's enrollment in the
Plan will terminate upon (i) the beginning of any payroll period or Offering
Period that begins after he or she files a written notice of termination of
enrollment with the Company, provided that such Participant will continue to be
deemed to be enrolled with respect to any completed Offering Period for which
purchases have not been completed, (ii) such time as the Participant becomes
ineligible to participate under Section 5(a) of the Plan, or (iii) the
termination of the Participant's employment by the Company and its Subsidiaries.
An employee whose enrollment in the Plan terminates may again enroll in the Plan
as of any subsequent Offering Period that is at least 90 days after such
termination of enrollment if he or she satisfies the eligibility requirements of
Section 5(a) as of such Offering Period. A Participant's election to discontinue
payroll contributions will not constitute a termination of enrollment.

            (b)   Distribution. As soon as practicable after a Participant's
enrollment in the Plan terminates, amounts in the Participant's Cash Account
which resulted from payroll contributions will be repaid to the Participant. The
Custodian will continue to maintain the Participant's Stock Account for the
Participant until the earlier of such time as the Participant directs the sale
of all Stock in the Account, withdraws, or transfers all Stock in the Account,
or one year after the Participant ceases to be employed by the Company and its
Subsidiaries. If a Participant's termination of enrollment results from his or
her death, all amounts payable will be paid to his or her estate.

      8.    GENERAL.

            (a)   Costs. Costs and expenses incurred in the administration of
the Plan and maintenance of Accounts will be paid by the Company, to the extent
provided in this Section 8(a). Any brokerage fees and commissions for the
purchase of Stock under the Plan (including Stock purchased upon reinvestment of
dividends and distributions) will be paid by the Company, but any brokerage fees
and commissions for the sale of Stock under the Plan by a Participant will be
borne by such Participant. The rate at which such fees and commissions will be
charged to Participants will be determined by the Custodian or any broker-dealer
used by the Custodian (including an affiliate of the Custodian), and
communicated from time to time to Participants. In addition, the Custodian may
impose or pass through a reasonable fee for the withdrawal of Stock


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in the form of stock certificates (as permitted under Section 6(d)), and
reasonable fees for other services unrelated to the purchase of Stock under the
Plan, to the extent approved in writing by the Company and communicated to
Participants.

            (b)   Statements to Participants. The Participant's statement will
reflect payroll contributions, purchases, sales, and withdrawals and transfers
of shares of Stock and other Plan transactions by appropriate adjustments to the
Participant's Accounts. The Custodian will, not less frequently than quarterly,
provide or cause to be provided a written statement to the Participant showing
the transactions in his or her Stock Account and the date thereof, the number of
shares of Stock credited or sold, the aggregate purchase price paid or sales
price received, the purchase or sales price per share, the brokerage fees and
commissions paid (if any), the total shares held for the Participant's Stock
Account (computed to at least three decimal places), and such other information
as agreed to by the Custodian and the Company.

            (c)   Compliance with Section 423. It is the intent of the Company
that this Plan comply in all respects with applicable requirements of Section
423 of the Code and regulations thereunder. Accordingly, if any provision of
this Plan does not comply with such requirements, such provision will be
construed or deemed amended to the extent necessary to conform to such
requirements.

      9.    GENERAL PROVISIONS.

            (a)   Compliance With Legal and Other Requirements. The Plan, the
granting and exercising of Purchase Rights hereunder, and the other obligations
of the Company and the Custodian under the Plan will be subject to all
applicable federal and state laws, rules, and regulations, and to such approvals
by any regulatory or governmental agency as may be required. The Company may, in
its discretion, postpone the issuance or delivery of Stock upon exercise of
Purchase Rights until completion of such registration or qualification of such
Stock or other required action under any federal or state law, rule, or
regulation, or the laws of any country in which employees of the Company and a
Subsidiary who are nonresident aliens and who are eligible to participate
reside, or other required action with respect to any automated quotation system
or stock exchange upon which the Stock or other Company securities are
designated or listed, or compliance with any other contractual obligation of the
Company, as the Company may consider appropriate. In addition, the Company may
require any Participant to make such representations and furnish such
information as it may consider appropriate in connection with the issuance or
delivery of Stock in compliance with applicable laws, rules, and regulations,
designation or listing requirements, or other contractual obligations.

            (b)   Limits on Encumbering Rights. No right or interest of a
Participant under the Plan, including any Purchase Right, may be pledged,
encumbered, or hypothecated to or in favor of any party, subject to any lien,
obligation, or liability of such Participant, or otherwise assigned,
transferred, or disposed of except pursuant to the laws of descent or
distribution, and any right of a Participant under the Plan will be exercisable
during the Participant's lifetime only by the Participant.



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            (c)   No Right to Continued Employment. Neither the Plan nor any
action taken hereunder, including the grant of a Purchase Right, will be
construed as giving any employee the right to be retained in the employ of the
Company or any of its Subsidiaries, nor will it interfere in any way with the
right of the Company or any of its Subsidiaries to terminate any employee's
employment at any time.

            (d)   Taxes. The Company or any Subsidiary is authorized to withhold
from any payment to be made to a Participant, including any payroll and other
payments not related to the Plan, amounts of withholding and other taxes due in
connection with any transaction under the Plan, and a Participant's enrollment
in the Plan will be deemed to constitute his or her consent to such withholding.
In addition, Participants may be required to advise the Company of sales and
other dispositions of Stock acquired under the plan in order to permit the
Company to comply with tax laws and to claim any tax deductions to which the
Company may be entitled with respect to the Plan. This provision and other Plan
provisions do not set forth an explanation of the tax consequences to
Participants under the Plan. A brief summary of the tax consequences will be
included in disclosure documents to be separately furnished to Participants.

            (e)   Changes to the Plan. The Board may amend, alter, suspend,
discontinue, or terminate the Plan without the consent of shareholders or
Participants, except that any such action will be subject to the approval of the
Company's shareholders within one year after such Board action if such
shareholder approval is required by any federal or state law or regulation or
the rules of any automated quotation system or stock exchange on which the Stock
may then be quoted or listed, or if such shareholder approval is necessary in
order for the Plan to continue to meet the requirements of Section 423 of the
Code, and the Board may otherwise, in its discretion, determine to submit other
such actions to shareholders for approval. However, without the consent of an
affected Participant, no amendment, alteration, suspension, discontinuation, or
termination of the Plan may materially and adversely affect the rights of such
Participant with respect to outstanding Purchase Rights relating to any Offering
Period that has been completed prior to such Board action. The foregoing
notwithstanding, upon termination of the Plan the Board may (i) elect to
terminate all outstanding Purchase Rights at such time as the Board may
designate, and all amounts contributed to the Plan which remain in a
Participant's Cash Account will be returned to the Participant (without
interest) as promptly as practicable, or (ii) shorten the Offering Period to
such period determined by the Board and use amounts credited to a Participant
Cash Account to purchase Stock.

            (f)   No Rights to Participate; No Shareholder Rights. No
Participant or employee will have any claim to participate in the Plan with
respect to Offering Periods that have not commenced, and the Company will have
no obligation to continue the Plan. No Purchase Right will confer on any
Participant any of the rights of a shareholder of the Company unless and until
Stock is duly issued or transferred and delivered to the Participant (or
credited to the Participant's Stock Account).

            (g)   Fractional Shares. Unless otherwise determined by the Board,
purchases of Stock under the Plan executed by the Custodian may result in the
crediting of fractional shares of Stock to the Participant's Stock Account. Such
fractional shares will be computed to at least three decimal places. Fractional
shares will not, however, be issued by the Company, and


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certificates representing fractional shares will not be delivered to
Participants under any circumstances.

            (h)   Plan Year. The Plan will operate on a plan year that begins on
January 1 and ends December 31 in each year.

            (i)   Governing Law. The validity, construction, and effect of the
Plan and any rules and regulations relating to the Plan will be determined in
accordance with the laws of the State of Arizona, without giving effect to
principles of conflicts of laws, and applicable federal law.

            (j)   Effective Date. The Plan will become effective on the IPO
Date, subject to the Plan being approved by shareholders of the Company, at a
meeting by a vote sufficient to meet the requirements of Section 423(b)(2) of
the Code. If the Plan is not approved in accordance with Section 423(b)(2) of
the Code, each Participant's Purchase Right shall be void and amounts credited
to the Participant's Cash Account shall be promptly returned to the Participant.










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