Exhibit 10.12
                             KLA-TENCOR CORPORATION

                GARY E. DICKERSON MANAGEMENT RETENTION AGREEMENT
This Agreement is made by and between KLA-Tencor Corporation (the "Company") and
Gary E. Dickerson ("Executive").

1. Duties and Scope of Employment.

(a) Position;  Agreement  Commencement Date; Duties.  Executive's coverage under
this  Agreement  shall  commence upon the date this Agreement has been signed by
both parties hereto (the "Agreement Commencement Date"). Following the Agreement
Commencement Date,  Executive shall continue to serve as Chief Operating Officer
of the  Company,  reporting  to the  Chief  Executive  Officer.  The  period  of
Executive's employment hereunder is referred to herein as the "Employment Term."
During  the  Employment   Term,   Executive   shall  render  such  business  and
professional  services  in  the  performance  of  his  duties,  consistent  with
Executive's  position within the Company, as shall reasonably be assigned to him
by the Chief Executive Officer.

(b)  Obligations.  During the Employment  Term,  Executive shall devote his full
business  efforts  and  time  to  the  Company.  Executive  agrees,  during  the
Employment Term, not to actively engage in any other  employment,  occupation or
consulting  activity for any direct or indirect  remuneration  without the prior
approval of the Board of  Directors  of the  Company  (the  "Board");  provided,
however, that Executive may serve in any capacity with any civic, educational or
charitable  organization,  or as a member of  corporate  Boards of  Directors or
committees  thereof,  without  the  approval of the Board,  unless such  service
involves a conflict of interest with the Company's business.

(c) Employee Benefits.  During the Employment Term,  Executive shall be eligible
to participate in the employee  benefit plans maintained by the Company that are
applicable  to other  senior  management  to the full extent  provided for under
those plans.

2. At-Will Employment. Executive and the Company understand and acknowledge that
Executive's  employment  with  the  Company  constitutes  "at-will"  employment.
Subject to the Company's  obligation to provide severance  benefits as specified
herein,  Executive and the Company acknowledge that this employment relationship
may be terminated at any time,  upon written notice to the other party,  with or
without good cause or for any or no cause,  at the option  either of the Company
or Executive.

3. Compensation.

(a) Base  Salary.  While  employed by the  Company,  the  Company  shall pay the
Executive as compensation  for his services a base salary at the annualized rate
of $454,922,  subject to temporary revision under the Company's Policy No. 30.01
(the "Base Salary").  Such salary shall be paid  periodically in accordance with
normal Company payroll practices and subject to the usual, required withholding.
Executive's Base Salary shall be reviewed annually by the Compensation Committee
of the Board  for  possible  adjustments  in light of  Executive's  performance,
market conditions and competitive data.

(b)  Bonuses.  Executive  shall be  eligible  to earn a target  bonus  under the
Company's  1996  Senior  Executive  Bonus  Plan  as  specified  annually  by the
Compensation Committee of the Board (the "Target Bonus").

(c)  Severance on or Within Two Years  Following a Change of Control.  If, on or
within two years  after a Change of Control  (as  defined  herein),  Executive's
employment  with the Company  terminates due to (i) a voluntary  termination for
"Good Reason" (as defined  herein),  or (ii) an  involuntary  termination by the
Company other than for "Cause" (as defined herein),  then,  subject to Executive
executing and not revoking a standard form of mutual  release of claims with the
Company and not breaching the terms of Section 11 hereof, (i) all of Executive's
Company  stock options shall  immediately  accelerate  vesting as to 100% of the
then unvested shares,  (ii) Executive shall receive continued  payments over two
years of Executive's Base Salary plus 100% of his Target Bonus,  less applicable
withholding,  in accordance with the Company's standard payroll practices; i.e.,
the total payout over the two-year  period shall be 200% of Base Salary and 200%
of Target Bonus (the "Severance  Payment"),  and (iii) the Company shall pay the
group  health,  dental  and  vision  plan  continuation  coverage  premiums  for
Executive and his covered  dependents under Title X of the  Consolidated  Budget
Reconciliation  Act of 1985, as amended  ("COBRA"),  or shall provide comparable
coverage,  if COBRA is not  available,  for the lesser of (A)  twenty-four  (24)
months from the date of Executive's  termination of employment,  or (B) the date
upon which Executive and his covered  dependents are covered by similar plans of
Executive's new employer (the "COBRA Coverage").

         For purposes of this Agreement, "Cause" shall mean
(i) an act of personal  dishonesty  taken by  Executive in  connection  with his
responsibilities  as an employee and intended to result in substantial  personal
enrichment of Executive,

(ii) Executive being convicted of, or plea of nolo contendere to, a felony,

(iii) a willful act by Executive which constitutes gross misconduct and which is
injurious  to the  Company,  (iv)  following  delivery to Executive of a written
demand  for  performance  from the  Company  which  describes  the basis for the
Company's  reasonable belief that Executive has not substantially  performed his
duties,  continued  violations by Executive of  Executive's  obligations  to the
Company which are demonstrably willful and deliberate on Executive's part.

For purposes of this Agreement, "Good Reason" means, without Executive's express
consent,

(i)  a  material   reduction  of  Executive's   duties,   title,   authority  or
responsibilities,   relative  to  Executive's   duties,   title,   authority  or
responsibilities  as in  effect  immediately  prior  to such  reduction,  or the
assignment   to  Employee  of  such   reduced   duties,   title,   authority  or
responsibilities

(ii) a reduction  by the Company in the Base  Salary of  Executive  as in effect
immediately prior to such reduction;

(iii) a material  reduction  by the Company in the  aggregate  level of employee
benefits or overall  compensation,  including Target Bonuses, to which Executive
was  entitled   immediately  prior  to  such  reduction  with  the  result  that
Executive's  aggregate  benefits  package is  materially  reduced  (other than a
reduction that generally applies to Company employees);

(iv)  the  relocation  of  Executive  to a  facility  or a  location  more  than
thirty-five (35) miles from Executive's then present location; or (v) any act or
set of facts or circumstances  which would, under California case law or statute
constitute a constructive termination of Executive.

For purposes of this Agreement, "Change of Control" shall mean the occurrence of
any of the following events:

(i) Any  "person"  (as such  term is used in  Sections  13(d)  and  14(d) of the
Securities  Exchange Act of 1934, as amended) becomes the "beneficial owner" (as
defined in Rule 13d-3 under said Act), directly or indirectly,  of securities of
the Company  representing  fifty percent (50%) or more of the total voting power
represented by the Company's then outstanding voting securities; or

(ii)  The  consummation  of the sale or  disposition  by the  Company  of all or
substantially all the Company's assets; or

(iii) The  consummation  of a merger or  consolidation  of the Company  with any
other  corporation,  other than 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) at least fifty percent (50%) of
the total voting power  represented  by the voting  securities of the Company or
such   surviving   entity   outstanding   immediately   after  such   merger  or
consolidation; or

(iv) A change  in the  composition  of the  Board  occurring  within a  two-year
period,  as a  result  of which  fewer  than a  majority  of the  directors  are
Incumbent Directors.  "Incumbent  Directors" shall mean directors who either (A)
are  directors  of the  Company  as of the date upon which  this  Agreement  was
entered into, or (B) are elected,  or nominated for election,  to the Board with
the  affirmative  votes of at least a majority of those directors whose election
or  nomination  was  not  in  connection  with  any  transaction   described  in
subsections  (i),  (ii),  or (iii)  above,  or in  connection  with an actual or
threatened proxy contest relating to the election of directors to the Company.

The  Executive  shall not be  required to  mitigate  the value of any  severance
benefits contemplated by this Agreement,  nor shall any such benefits be reduced
by any  earnings  or benefits  that the  Executive  may  receive  from any other
source;  provided,  however,  that  Executive  if Executive  receives  severance
benefits hereunder,  he expressly waives the right to receive severance benefits
under any other severance plan or policy of the Company.

(d) Voluntary  Termination Other than for Good Reason;  Involuntary  Termination
for Cause  Following  a Change of  Control;  Employment  Termination  Prior to a
Change of  Control.  In the  event,  (i)  following  a Change of  Control,  that
Executive terminates his employment voluntarily other than for Good Reason or is
involuntarily   terminated  by  the  Company  for  Cause,  or  (ii)  Executive's
employment  terminates  for any or no reason prior to a Change of Control,  then
all vesting of Executive's  stock options and restricted  stock shall  terminate
immediately  and all  payments  of  compensation  by the  Company  to  Executive
hereunder shall immediately terminate (except as to amounts already earned).

4. Death or Total Disability of Executive.  Upon  Executive's  death or becoming
permanently and totally disabled (as defined in accordance with Internal Revenue
Code Section 22(e)(3) or its successor provision) while Executive is an employee
or consultant of the Company,  then (i) employment hereunder shall automatically
terminate and all payments of compensation by the Company to Executive hereunder
shall  immediately  terminate  (except as to amounts  already  earned),  and all
vesting of  Executive's  stock  options and  restricted  stock  shall  terminate
immediately.


5. Golden Parachute Excise Taxes.

(a) Parachute  Payments of Less than 3x Base Amount Plus Fifty Thousand Dollars.
In the event that the  benefits  provided  for in this  agreement  or  otherwise
payable to Employee (a) constitute  "parachute  payments"  within the meaning of
Section 280G of the Internal Revenue Code of 1986, as amended (the "Code"),  (b)
would be subject to the excise tax imposed by Section 4999 of the Code,  and (c)
the aggregate value of such parachute payments, as determined in accordance with
Section 280G of the Code and the proposed  Treasury  Regulations  thereunder (or
the final Treasury Regulations, if they have then been adopted) is less than the
product  obtained by  multiplying  three by Employee's  "base amount" within the
meaning of Code Section  280G(b)(3)  and adding to such product  fifty  thousand
dollars,  then such benefits shall be reduced to the extent  necessary (but only
to that  extent) so that no portion of such  benefits  will be subject to excise
tax under Section 4999 of the Code.

(b)  Parachute  Payments  Equal to or  Greater  than 3x Base  Amount  Plus Fifty
Thousand Dollars.  In the event that the benefits provided for in this agreement
or otherwise payable to Employee (a) constitute  "parachute payments" within the
meaning  of  Section  280G of the Code,  (b) would be  subject to the excise tax
imposed  by  Section  4999 of the  Code,  and (c) the  aggregate  value  of such
parachute  payments,  as determined in accordance  with Section 280G of the Code
and  the  proposed  Treasury  Regulations  thereunder  (or  the  final  Treasury
Regulations,  if they have then been  adopted)  is equal to or greater  than the
product  obtained by  multiplying  three by Employee's  "base amount" within the
meaning of Code Section  280G(b)(3)  and adding to such product  fifty  thousand
dollars, then the benefits shall be delivered in full.

(c) 280G Determinations.  Unless the Company and the Employee otherwise agree in
writing,  the  determination  of Employee's  excise tax liability and the amount
required to be paid or reduced  under this Section 5 shall be made in writing by
the  Company's  independent  auditors  who are  primarily  used  by the  Company
immediately prior to the Change of Control (the "Accountants").  For purposes of
making the  calculations  required by this Section 5, the  Accountants  may make
reasonable  assumptions and approximations  concerning  applicable taxes and may
rely on reasonable,  good faith  interpretations  concerning the  application of
Sections 280G and 4999 of the Code.  The Company and the Employee  shall furnish
to the  Accountants  such  information  and  documents  as the  Accountants  may
reasonably  request in order to make a  determination  under this  Section.  The
Company shall bear all costs the Accountants may reasonably  incur in connection
with any calculations contemplated by this Section 5.

6. Assignment. This Agreement shall be binding upon and inure to the benefit of

(a) the heirs,  beneficiaries,  executors and legal representatives of Executive
upon Executive's death and

(b) any  successor of the Company.  Any such  successor of the Company  shall be
deemed  substituted  for the Company  under the terms of this  Agreement for all
purposes.   As  used  herein,   "successor"  shall  include  any  person,  firm,
corporation  or other  business  entity which at any time,  whether by purchase,
merger or otherwise, directly or indirectly acquires all or substantially all of
the  assets or  business  of the  Company.  None of the rights of  Executive  to
receive any form of  compensation  payable  pursuant to this Agreement  shall be
assignable or transferable  except through a testamentary  disposition or by the
laws of descent and  distribution  upon the death of  Executive.  Any  attempted
assignment,  transfer, conveyance or other disposition (other than as aforesaid)
of any interest in the rights of  Executive to receive any form of  compensation
hereunder shall be null and void.

7. Notices. All notices,  requests,  demands and other communications called for
hereunder  shall be in  writing  and  shall  be  deemed  given if (i)  delivered
personally or by facsimile, (ii) one (1) day after being sent by Federal Express
or a similar commercial  overnight service,  or (iii) three (3) days after being
mailed by registered or certified mail,  return receipt  requested,  prepaid and
addressed  to the  parties or their  successors  in  interest  at the  following
addresses,  or at such other  addresses as the parties may  designate by written
notice in the manner aforesaid:

         If to the Company:             KLA-Tencor Corporation
                                        160 Rio Robles
                                        San Jose, CA  95134
                                        Attn: General Counsel

         If to Executive:               Gary E. Dickerson
                                        at the last residential address known
                                        by the Company.

8.  Severability.  In the event that any provision hereof becomes or is declared
by a court of competent jurisdiction to be illegal,  unenforceable or void, this
Agreement shall continue in full force and effect without said provision.

9. Entire Agreement.  This Agreement,  the Employee Proprietary  Information and
Inventions  Agreement  previously  entered  into by and  between the Company and
Executive  and the  indemnification  agreement  previously  entered  into by and
between  the  Company  and  Executive   represent   the  entire   agreement  and
understanding   between  the  Company  and  Executive   concerning   Executive's
employment  relationship with the Company, and supersede and replace any and all
prior   agreements  and   understandings   concerning   Executive's   employment
relationship with the Company.

10. Dispute Resolution.

(a) The  parties  shall  first meet to settle  any  dispute  through  good faith
negotiation or non-binding  mediation.  If not settled by good faith negotiation
or  non-binding  mediation  between the parties within 30 days from the date one
party requests in writing to meet the other party,  then to the extent permitted
by law, any dispute or controversy arising out of, relating to, or in connection
with this Agreement, or the interpretation, validity, construction, performance,
breach, or termination  thereof shall be finally settled by binding  arbitration
to be held in Santa Clara County,  California,  in accordance  with the National
Rules for the  Resolution of Employment  Disputes then in effect of the American
Arbitration  Association (the "Rules").  The arbitrator may grant injunctions or
other relief in such  dispute or  controversy.  The  decision of the  arbitrator
shall be  confidential,  final,  conclusive  and  binding on the  parties to the
arbitration.   Judgment  may  be  entered  under  a  protective   order  on  the
arbitrator's  decision in any court having  jurisdiction.  The Company shall pay
all costs of any mediation or arbitration;  provided,  however,  that each party
shall pay its own attorney and advisor fees.

(b) The  arbitrator  shall apply  California law to the merits of any dispute or
claim,   without  reference  to  rules  of  conflict  of  law.  The  arbitration
proceedings  shall be  governed  by  federal  arbitration  law and by the Rules,
without reference to state arbitration law.  Executive hereby expressly consents
to the  personal  jurisdiction  of the  state  and  federal  courts  located  in
California  for any  action  or  proceeding  arising  from or  relating  to this
Agreement   and/or  relating  to  any  arbitration  in  which  the  parties  are
participants.

(c)  Executive  understands  that  nothing in Section  10  modifies  Executive's
at-will  status.  Either the Company or Executive can  terminate the  employment
relationship at any time, with or without cause.

(d) EXECUTIVE HAS READ AND UNDERSTANDS SECTION 10, WHICH DISCUSSES  ARBITRATION.
EXECUTIVE  UNDERSTANDS THAT BY SIGNING THIS AGREEMENT,  EXECUTIVE AGREES, TO THE
EXTENT  PERMITTED BY LAW, TO SUBMIT ANY FUTURE CLAIMS  ARISING OUT OF,  RELATING
TO, OR IN  CONNECTION  WITH THIS  AGREEMENT,  OR THE  INTERPRETATION,  VALIDITY,
CONSTRUCTION,   PERFORMANCE,   BREACH,   OR   TERMINATION   THEREOF  TO  BINDING
ARBITRATION,   AND  THAT  THIS  ARBITRATION   CLAUSE  CONSTITUTES  A  WAIVER  OF
EXECUTIVE'S  RIGHT TO A JURY TRIAL AND RELATES TO THE RESOLUTION OF ALL DISPUTES
RELATING TO ALL ASPECTS OF THE EMPLOYER/EMPLOYEE RELATIONSHIP.

11. Covenants Not to Compete and Not to Solicit.

(a) Covenant Not to Compete. Executive agrees that, if he is receiving severance
benefits pursuant to Section 3(c) hereof,  then until the end of the twenty four
month  period  following  the date of his  termination  of  employment  with the
Company  for any  reason or no reason,  Executive  will not  directly  engage in
(whether  as  an  employee,   consultant,   proprietor,   partner,  director  or
otherwise),  or have any ownership interest in, or participate in the financing,
operation,  management or control of, any person, firm,  corporation or business
that  engages  or  participates  anywhere  in the world in  providing  goods and
services  similar to those  provided by the Company upon the date of Executive's
termination of employment.  Ownership of less than 3% of the outstanding  voting
stock of a corporation  or other entity will not  constitute a violation of this
provision.  The  Company  agrees  not  to  unreasonably  withhold  consent  from
Executive to engage in any activity that is not competitive with the Company.

(b) Covenant Not to Solicit. Executive agrees that, if he is receiving severance
benefits  pursuant to Section 3(c)  hereof,  he will not, at any time during the
twelve month period  following  his  termination  date,  directly or  indirectly
solicit  any  individuals  to leave  the  Company's  employ  for any  reason  or
interfere  in any other  manner with the  employment  relationships  at the time
existing between the Company and its current or prospective employees.

(c) Representations.  The parties intend that the covenants contained in Section
11(a) and (b) shall be construed as a series of separate covenants, one for each
county,  city and state (or analogous  entity) and country of the world.  If, in
any  judicial  proceeding,  a court shall  refuse to enforce any of the separate
covenants,  or any part thereof, then such unenforceable  covenant, or such part
thereof, shall be deemed eliminated from this Agreement for the purpose of those
proceedings to the extent necessary to permit the remaining separate  covenants,
or portions thereof, to be enforced.

(d) Reformation. In the event that the provisions of this Section 11 should ever
be  deemed  to  exceed  the  time or  geographic  limitations,  or scope of this
covenant, permitted by applicable law, then such provisions shall be reformed to
the maximum time or  geographic  limitations,  as the case may be,  permitted by
applicable laws.

(e)  Reasonableness  of Covenants.  Employee  represents that he (i) is familiar
with the  covenants  not to compete and solicit,  and (ii) is fully aware of his
obligations hereunder,  including, without limitation, the reasonableness of the
length of time, scope and geographic coverage of these covenants.

12. No Oral Modification,  Cancellation or Discharge. This Agreement may only be
amended,  canceled or discharged in writing signed by Executive and the Chairman
of the Board.

13.  Withholding.  The Company  shall be entitled  to  withhold,  or cause to be
withheld,  from  payment any amount of  withholding  taxes  required by law with
respect  to  payments  made to  Executive  in  connection  with  his  employment
hereunder.

14.  Governing Law. This Agreement shall be governed by the laws of the State of
California.

15.  Effective  Date.  This  Agreement  is  effective  upon the date it has been
executed by both parties.


16.  Acknowledgment.  Executive  acknowledges that he has had the opportunity to
discuss this matter with and obtain  advice from his private  attorney,  has had
sufficient  time to,  and has  carefully  read  and  fully  understands  all the
provisions of this  Agreement,  and is knowingly and  voluntarily  entering into
this Agreement.




IN WITNESS WHEREOF, the undersigned have executed this Agreement:


KLA-TENCOR CORPORATION

/s/ KENNETH L. SCHROEDER
- --------------------------
Kenneth L. Schroeder



EXECUTIVE

/s/ GARY E. DICKERSON
- ----------------------
Gary E. Dickerson


Date: November 26, 2001