EXHIBIT 10e
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                                   ----------

                             KEY EMPLOYEE AGREEMENT

                                   ----------

To:  Brian R. Chisholm                                   As of November 26, 1996
     10150 Parkwood Drive, Apartment 4
     Cupertino, California  95014

         The  undersigned,  Applied  Science and  Technology,  Inc.,  a Delaware
corporation,  as well as its  successors and assigns  (hereinafter  collectively
referred to as the "Company"), hereby agree with you as follows:

         l. Position and Responsibilities.

            1.1 You shall serve as Senior Vice  President of  Operations  of the
Company  (or in such other  executive  capacity  as shall be  designated  by the
President or Board of Directors and be reasonably  acceptable to you). You will,
to the best of your  ability,  devote  your  full time and best  efforts  to the
performance of your duties hereunder and the business and affairs of the Company
and perform such  executive  duties as may be assigned to you by or on authority
of the  Company's  President  and Board of  Directors  from time to time and the
duties customarily associated with such executive capacity from time to time and
at such place or places as the  Company  shall  designate  are  appropriate  and
necessary in connection with such employment;  provided, however, that you shall
not be required to relocate your place of  employment  beyond a twenty (20) mile
radius from Woburn, Massachusetts without your prior written consent.

            1.2 You will duly, punctually and faithfully perform and observe any
and all  rules and  regulations  which the  Company  may now or shall  hereafter
establish governing the conduct of its business.

            1.3 You will report directly to the Company's President.

         2. Term of Employment.

            2.1 The initial term of this  Agreement  shall be for the period set
forth on Exhibit A annexed hereto  commencing with the date hereof.  Thereafter,
this Agreement  shall be  automatically  renewed for  successive  periods of one
year,  unless you or the Company shall give the other party not less than thirty
(30) days written notice of non-renewal. Your employment with the Company may be
terminated as provided in Section 2.2 .



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            2.2 The Company shall have the right, upon written notice to you, to
terminate your employment:

                (a)  immediately  at any time for  "Cause"  (as  defined  herein
          subject  to your right of cure and right to  dispute  as  provided  in
          Section 2.3 herein); or

                (b) at any time,  without  "Cause,"  provided  that the  Company
          shall be obligated to pay to you the  Severance  Benefits set forth in
          Sections 6 or 7, as  applicable,  of Exhibit A, plus any sums then due
          to you,  including  those expenses as are provided for in Section 8 of
          Exhibit A, less (i) applicable taxes and other required  withholdings,
          and (ii) any amounts you may owe to the Company.  Payments  under this
          Section 2.2 (b) shall not be due or payable if you are  terminated  at
          any  time  for  "Cause"  or  if  you  voluntarily   resign  from  your
          employment, except as set forth in Section 7 of Exhibit A.

            2.3 For purposes of Section  2.2,  the term  "Cause"  shall mean (a)
gross  negligence  in the  performance  of assigned  duties;  (b)  material  and
repetitive  refusal  to  perform or  discharge  the  duties or  responsibilities
assigned  by the Board of  Directors  of the Company  provided  the same are not
illegal, unethical or inconsistent with the position of Senior Vice President of
Operations of a corporation  and the failure to correct such refusal and perform
such duties or  responsibilities  within a reasonable period of time (but in any
event no less  than  seven  (7)  calendar  days  after  written  notice  of such
failure);  (c) conviction of a felony involving moral turpitude;  (d) willful or
prolonged  absence  from work not excused by a bona fide medical  disability  as
reasonably  determined by a qualified  physician mutually acceptable to both you
and the  Company or other good cause as  reasonably  determined  by the Board of
Directors;  and (e) falseness of any warranty or representation by you herein or
the breach of your obligations under this Agreement to the material detriment of
the Company.  Any dispute,  controversy,  or claim arising out of, in connection
with,  or in  relation  to  the  definition  of  "Cause"  shall  be  settled  by
arbitration in accordance with the terms of Section 17 hereof.

            2.4 In the  event of the  Involuntary  Termination  (as  hereinafter
defined) of your  employment  with the Company at any time,  the Company  hereby
irrevocably  agrees to provide you with Severance Benefits as defined in Section
6 of  Exhibit A hereto or  payments  in the event of a "Change  in  Control"  as
defined  in  Section 7 of Exhibit  A. In this  regard,  the phrase  "Involuntary
Termination"  shall mean (a) any  termination of your  employment by the Company
other than for "cause," as defined in Section 2.3, (b) any notice by the Company
not to renew this  Agreement  pursuant to Section  2.1,  or (c) for  purposes of
Section 7 of Exhibit A (but not Section 6 of Exhibit A) any  termination of your
employment by you due to any of the following circumstances:  (i) a reduction in
your Base Salary or Company-paid benefits,  (ii) a reduction in your eligibility
for any Company bonus or other benefit program,  (iii) a material or substantial
change in your title,  position,  authority or duties,  or (iv) a change of your
principal  place of employment to a location beyond twenty (20) miles of Woburn,
Massachusetts.



                                       









            2.5 You shall have the right to terminate this Agreement upon
not less than thirty (30) days prior written notice to the Company.

         3.  Compensation.  You shall receive the  compensation and benefits set
forth on Exhibit A  ("Compensation")  for all  services  to be  rendered  by you
hereunder  and for your  transfer of property  rights  pursuant to an  agreement
relating  to  proprietary  information  and  inventions  of even  date  herewith
attached  hereto as  Exhibit C between  you and the  Company  (the  "Proprietary
Information and Inventions Agreement").

         4. Other Activities During Employment.

            4.1 Except for any outside  employments and directorships  currently
held by you as listed on Exhibit B, and except with the prior written consent of
the Company's Board of Directors, you will not during the term of this Agreement
undertake or engage in any other employment,  occupation or business  enterprise
other than one in which you are an inactive investor.

            4.2 You hereby agree that,  except as disclosed on Exhibit B hereto,
during your employment hereunder,  you will not, directly or indirectly,  engage
(a) individually,  (b) as an officer, (c) as a director, (d) as an employee, (e)
as a consultant,  (f) as an advisor,  (g) as an agent  (whether a salesperson or
otherwise),  (h) as a broker,  or (i) as a partner,  coventurer,  stockholder or
other  proprietor  owning  directly or  indirectly  more than two  percent  (2%)
interest, in any firm, corporation,  partnership,  trust, association,  or other
organization  which  is  engaged  in  the  research,  development,   production,
manufacture  or marketing of equipment or processes in direct  competition  with
the  Company or any other  line of  business  engaged  in or under  demonstrable
development  by  the  Company  (such  firm,  corporation,   partnership,  trust,
association,   or  other  organization  being  hereinafter   referred  to  as  a
"Prohibited  Enterprise").  Except  as may be shown  on  Exhibit  B, you  hereby
represent  that  you are not  engaged  in any of the  foregoing  capacities  (a)
through (i) in any Prohibited Enterprise.

         5. Former Employers.

            5.1 You  represent  and warrant that your  employment by the Company
will not  conflict  with and will not be  constrained  by any  prior or  current
employment,  consulting  agreement or relationship  whether oral or written. You
represent and warrant that you do not possess  confidential  information arising
out of any such employment,  consulting agreement or relationship which, in your
best  judgment,  would be utilized in  connection  with your  employment  by the
Company in the absence of Section 5.2.

            5.2 If, in spite of the second  sentence of Section  5.1, you should
find that confidential information belonging to any other person or entity might
be usable in connection with the Company's business,  you will not intentionally
disclose  to the  Company  or use on  behalf  of the  Company  any  confidential
information  belonging  to  any  of  your  former  employers;  but  during  your
employment  by the  Company you will use in the  performance  of your duties all
information  which 


                                      -3-





is generally  known and used by persons with training and experience  comparable
to your own all  information  which  is  common  knowledge  in the  industry  or
otherwise legally in the public domain.

         6.  Proprietary  Information  and  Inventions.  You  agree to  execute,
deliver  and be bound  by the  provisions  of the  Proprietary  Information  and
Inventions Agreement.

         7. Post-Employment Activities.

            7.1 For a period of two (2) years (or for a lesser period should the
Company so determine)  after the termination or expiration,  for any reason,  of
your employment with the Company  hereunder,  absent the Company's prior written
approval,  you will not directly or indirectly  engage in activities  similar or
reasonably related to those in which you shall have engaged hereunder during the
two years  immediately  preceding  termination  or  expiration  for,  nor render
services  similar or  reasonably  related to those which you shall have rendered
hereunder during such two years to, any person or entity whether now existing or
hereafter  established  which  directly  competes  with (or proposes or plans to
directly compete with) the Company ("Direct Competitor") in any line of business
engaged in or under development by the Company. Nor shall you entice,  induce or
encourage any of the Company's  other employees to engage in any activity which,
were it done by you, would violate any provision of the Proprietary  Information
and  Inventions  Agreement  or this  Section 7. As used in this Section 7.1, the
term "any line of business engaged in or under development by the Company" shall
be applied as at the date of termination of your employment, or, if later, as at
the date of termination of any post-employment consultation.

            7.2 For a period of two (2)  years  after  the  termination  of your
employment  with the Company,  the provisions of Section 4.2 shall be applicable
to you  and you  shall  comply  therewith.  As  applied  to  such  two (2)  year
post-employment period, the term "any other line of business engaged in or under
development  by the Company," as used in Section 4.2, shall be applied as at the
date of termination of your  employment with the Company or, if later, as at the
date of termination of any post-employment consultation with the Company.

            7.3 No  provision of this  Agreement  shall be construed to preclude
you from  performing  the same services  which the Company hereby retains you to
perform for any person or entity which is not a Direct Competitor of the Company
upon the expiration or termination  of your  employment (or any  post-employment
consultation)  so long as you do not thereby violate any term of the Proprietary
Information and Inventions Agreement.

         8. Remedies.  Your  obligations  under the Proprietary  Information and
Inventions Agreement and the provisions of Sections 4, 6, 7, 8, 9 and 17 of this
Agreement  (as  modified  by  Section  10,  if  applicable)  shall  survive  the
expiration or termination of your employment  (whether  through your resignation
or otherwise)  with the Company.  You  acknowledge  that a remedy at law for any
breach  or  threatened  breach  by  you  of the  provisions  of the  Proprietary
Information and Inventions Agreement or Section 7 hereof would be inadequate and
you  therefore  agree that the


                                      -4-




Company shall be entitled to such injunctive or other  equitable  relief in case
of any such breach or threatened breach.

         9.  Assignment.  This  Agreement and the rights and  obligations of the
parties  hereto  shall  bind  and  inure  to the  benefit  of any  successor  or
successors of the Company by  reorganization,  merger or  consolidation  and any
assignee of all or substantially all of its business and properties, but, except
as to any such successor or assignee of the Company,  neither this Agreement nor
any rights or  benefits  hereunder  may be  assigned  by the  Company or by you,
except  by  operation  of  law.  The  Company's  obligations  and  those  of any
successors or assignees of the Company under this  Agreement,  including but not
limited to the severance  provisions and other  compensation and benefits due to
you pursuant to Exhibit A hereto, will be a condition of and are to remain those
of any successor or assignee.

         10.  Interpretation.  IT IS THE INTENT OF THE PARTIES  THAT in case any
one or more of the provisions contained in this Agreement shall, for any reason,
be held to be invalid, illegal or unenforceable in any respect, such invalidity,
illegality  or  unenforceability  shall not affect the other  provisions of this
Agreement,  and this Agreement shall be construed as if such invalid, illegal or
unenforceable  provision had never been contained  herein.  MOREOVER,  IT IS THE
INTENT OF THE PARTIES THAT in case any one or more of the  provisions  contained
in this  Agreement  shall for any reason be held to be  excessively  broad as to
duration,  geographical  scope,  activity or subject,  such  provision  shall be
construed  by limiting  and  reducing it as  determined  by a court of competent
jurisdiction,  so as to be enforceable to the extent  compatible with applicable
law.

         11. Notices.  Any notice which the Company is required to or may desire
to give you shall be given by personal delivery or registered or certified mail,
return  receipt  requested,  addressed to you at your address of record with the
Company,  or at such  other  place as you may  from  time to time  designate  in
writing.  Any notice which you are required or may desire to give to the Company
hereunder  shall be given by personal  delivery or by  registered  or  certified
mail,  return  receipt  requested,  addressed  to the  Company at its  principal
office,  or at such other office as the Company may from time to time  designate
in  writing.  The date of  personal  delivery  or the date of mailing any notice
under this Section 11 shall be deemed to be the date of delivery thereof.

         12.  Waivers.  If either party should waive any breach of any provision
of this  Agreement,  such party  shall not  thereby be deemed to have waived any
preceding  or  succeeding  breach  of the same or any  other  provision  of this
Agreement.

         13. Complete Agreement; Amendments. The foregoing including Exhibits A,
B and C hereto,  is the entire  agreement  of the  parties  with  respect to the
subject matter hereof,  superseding any previous oral or written communications,
representations,  understandings,  or agreements with the Company or any officer
or  representative  thereof.  Any  amendment to this  Agreement or waiver by the
Company of any right hereunder shall be effective only if evidenced by a written
instrument  executed by the parties hereto,  upon authorization of the Company's
Board of Directors.


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         14.  Headings.  The  headings of the  Sections  hereof are inserted for
convenience  only and shall not be deemed to  constitute  a part  hereof  nor to
affect the meaning of this Agreement.

         15.  Counterparts.  This  Agreement may be signed in two  counterparts,
each of which  shall be  deemed an  original  and both of which  shall  together
constitute one agreement.

         16.  Governing Law. This  Agreement  shall be governed by and construed
under Massachusetts law.

         17.  Arbitration  of Disputes.  Subject to the rights of the parties to
seek injunctive relief as described herein, any controversy or claim arising out
of, or relating to, any provision of this Agreement  shall be settled by binding
arbitration in accordance with the laws of the  Commonwealth of Massachusetts by
three  arbitrators,  one of whom shall be appointed by the Company,  one of whom
shall be appointed by you,  and the third  arbitrator  who shall be appointed by
the first two  arbitrators.  If the first two  arbitrators  cannot  agree on the
appointment of a third arbitrator,  then the third arbitrator shall be appointed
by the American Arbitration  Association in the City of Boston. Such arbitration
shall be  conducted  in the City of Boston in  accordance  with the rules of the
American  Arbitration  Association,  except  with  respect to the  selection  of
arbitrators,  which shall be as provided in this Section.  Judgment on the award
or  determination  rendered  by the  arbitrators  shall be  final,  binding  and
conclusive upon the parties, and may be entered in any court having jurisdiction
thereof and shall not be appealable.  The prevailing  party in such  arbitration
proceeding  shall  be  entitled  to  reimbursement  by the  other  party  of all
reasonable  legal  fees and other  costs  incurred  by the  prevailing  party in
connection with such proceeding,  including any legal fees and costs incurred in
connection with the enforcement of any award.

         18. Advice of Separate Counsel.  The Company has requested that the law
firm of  O'Connor,  Broude &  Aronson  prepare  this  document  on behalf of the
Company.  You  acknowledge  that you have been advised to review this  Agreement
with your own legal  counsel and other  advisors of your choosing and that prior
to entering into this  Agreement,  you have had the  opportunity  to review this
Agreement  with your  attorney and other  advisors and have not asked (or relied
upon) O'Connor, Broude & Aronson to represent you in this matter.






                    [THIS SPACE IS INTENTIONALLY LEFT BLANK]


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         If you are in agreement with the foregoing, please sign your name below
and also at the bottom of the Proprietary  Information and Inventions Agreement,
whereupon  this  Agreement  shall become  binding in accordance  with its terms.
Please then  return  this  Agreement  to the  Company.  (You may retain for your
records the accompanying counterpart of this Agreement enclosed herewith).


ACCEPTED AND AGREED:               APPLIED SCIENCE AND TECHNOLOGY, INC.




                                   By:                                          
-----------------------------         ------------------------------------
Brian R. Chisholm                     Dr. Richard S. Post, President



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                                                                       EXHIBIT A


                   EMPLOYMENT TERM, COMPENSATION AND BENEFITS
                              OF BRIAN R. CHISHOLM


         l. Term.  The term of the Agreement to which this Exhibit A is attached
and made a part shall be for a period  from the date of this  Agreement  through
December 31, 1997.

         2. Compensation.

            (a)  Base  Salary.   Your  base  salary  ("Base  Salary")  shall  be
$134,000.00  per annum  through April 1, 1997,  payable in  accordance  with the
Company's payroll policies at the rate of $11,166.66 per month. Commencing April
1, 1997,  your Base Salary shall be increased to $147,400 per annum,  payable at
the rate of  $12,283.33  per month and shall  thereafter as  established  by the
Board of Directors or Compensation Committee.

            (b)  Bonuses.  Fiscal  1996 and 1997.  The Company  shall  establish
appropriate  incentive  compensation  plans ("Bonuses") for you each fiscal year
that you are employed  hereunder.  You shall be entitled to a bonus of up to 35%
of your then current Base Salary by the  Company=s  Compensation  Committee  and
ratified by the  Company=s  Board of  Directors.  Such Bonuses shall be properly
approved by the Board of Directors or any committee  established  and authorized
to perform such duties by the Board of Directors.

         3. Vacation.  You shall be entitled to all legal holidays recognized by
the Company , and 18 days paid  vacation per annum.  Any unused  vacation may be
accrued or used in accordance with Company policy.

         4. Insurance and Benefits.  You shall be eligible for  participation in
any health, dental, and other group insurance plans which may be established and
maintained  by the Company for all  full-time  employees or which the Company is
required to maintain by law. The Company shall provide you with health insurance
for you and your family providing benefits at least equal to the benefits of the
policies  currently  in place and shall  provide  you with group life  insurance
equal to two times your base salary.  You shall also be entitled to  participate
in any employee  benefit  programs  which the  Company's  Board of Directors may
establish for its key employees, or for its employees generally,  including, but
not limited to, bonuses and stock purchase or option plans. You will be eligible
to participate in the Company's 401(k) Plan.

         5.  Relocation  Reimbursement.  The  Company  shall pay for the cost of
airfare (in  accordance  with the Company=s  travel policy) for you to travel to
Boston  from  California  on two  roundtrips.  The  Company  shall also pay your
reasonable  moving and temporary  storage expenses (for up to three (3) months),
not to exceed  $7,500.00.  The Company shall also pay the cost of a mid-


                                      A-1









size car  rental for a one month  period  starting  January  5,  1997,  and will
reimburse  you for  temporary  housing at the Marriott  Residence Inn or similar
temporary residence  acceptable to both you and the Company not to exceed ninety
(90) days.  Should you incur the loss of your  security  deposit or other rental
charges  associated  with  terminating  your current  lease,  the Company  shall
reimburse you for such costs up to an amount not to exceed $2,800.00.

         6. Severance Benefits.

            (a) When  provided for in this  Agreement,  you shall be entitled to
"Severance Benefits." When used in this Agreement, the term "Severance Benefits"
shall mean a total  amount  equal to (i) your then  current  annual Base Salary,
plus (ii) your Bonuses  earned for the Company's most recent fiscal year. If the
Company's  fiscal year is changed,  the Bonuses shall be based upon your bonuses
received  during the Company's most recent fiscal year.  The Severance  Benefits
shall be paid  via  check  to you in  twelve  (12)  equal  monthly  installments
commencing within ten (10) days after the date of your termination of employment
with the Company.

            (b) In addition,  the term  "Severance  Benefits"  shall include the
continuation for you and your family,  during the Severance  Period,  as defined
below,  of all of the other  benefits  which are provided or available to you on
the last day of your actual  service with the Company,  including your continued
accrual  and the  vesting  under the terms of any  pension  or 401(k)  plan then
sponsored by the Company to the maximum extent permitted by law. For purposes of
this  Agreement,  the term  "Severance  Period"  means the period of twelve (12)
months beginning on the Date of Termination.

            (c) The Severance Benefits referred to above will be in addition to,
and not in substitution for, any accrued and unpaid salary,  vacation,  pension,
retirement or other benefits,  unreimbursed  expenses or other payments to which
you may be otherwise entitled.

            (d) In the  event  of  your  death  while  you are  employed  by the
Company,  your then current Base Salary shall  continue to be paid to your legal
representative for a period of 60 days following the date of your death; and for
a period of one (1) years  following  your death,  the Company shall continue to
provide to your spouse at Company cost the health insurance  coverage  described
above.

            (e) You shall not be required to mitigate  the amount of any payment
the Company becomes  obligated to make to you in connection with this Agreement,
by seeking other employment or otherwise.

         7. Change in Control.

            (a) For purposes of this  Agreement,  "Change in Control"  means and
shall be deemed to occur if any of the following occurs:  (i) the acquisition by
an individual,  entity or group,  as defined in Section  13(d)(3) or 14(d)(2) of
the Securities Exchange Act of 1934, as amended (the


                                      A-2






"Exchange Act"), of beneficial  ownership,  as defined in Rule 13d-3 promulgated
under the Exchange Act, of 50% or more of either (A) the  outstanding  shares of
common stock, $ .01 par value per share, of the Company (the "Common Stock"), or
(B) the combined voting power of the voting  securities of the Company  entitled
to vote  generally in the election of directors  (the "Voting  Securities");  or
(ii) individuals  who, on April 30, 1996,  constituted the Board of Directors of
the Company (the "Incumbent  Board") cease for any reason to constitute at least
a majority of the Board of Directors of the Company; provided, however, that any
individual  becoming a director  subsequent to July 1, 1995, whose election,  or
nomination for election by the Company's shareholders, was approved by a vote of
at least a majority of the directors  then serving and  comprising the Incumbent
Board  shall be  considered  as  though  such  individual  were a member  of the
Incumbent  Board,  but excluding,  for this purpose,  any such individual  whose
initial  assumption  of  office  occurs  as a result  of  either  an  actual  or
threatened election contest (as such terms are used in Rule 14a-11 of Regulation
14A  promulgated   under  the  Exchange  Act)  or  other  actual  or  threatened
solicitation of proxies or consents; or (iii) approval by the Board of Directors
or the  shareholders  of the Company of a (A) tender offer to acquire any of the
Common  Stock or  voting  securities,  (B)  reorganization,  (C)  merger  or (D)
consolidation, other than a reorganization, merger or consolidation with respect
to which all or  substantially  all of the individuals and entities who were the
beneficial  owners,   immediately  prior  to  such  reorganization,   merger  or
consolidation,  of the Common  Stock and  voting  securities  beneficially  own,
directly  or  indirectly,  immediately  after  such  reorganization,  merger  or
consolidation,  more than 80% of the then  outstanding  common  stock and voting
securities  (entitled to vote  generally in the  election of  directors)  of the
Company  resulting  from  such   reorganization,   merger  or  consolidation  in
substantially  the same proportions as their respective  ownership,  immediately
prior to such reorganization,  merger or consolidation,  of the Common Stock and
the  voting  securities;  or (iv)  Approval  by the  Board of  Directors  or the
shareholders  of the Company of (A) a complete  or  substantial  liquidation  or
dissolution  of the  Company,  or (B) the  sale or other  disposition  of all or
substantially  all of the assets of the Company,  excluding a reorganization  of
the Corporation under the corporate laws of a state of Delaware.

            (b) In the  event of a Change  in  Control  during  the term of this
Agreement or any renewal or extension hereof and provided you remain employed by
the  Company  for a period of 12 months  from the date of the Change in Control,
you will  receive,  at the  one-year  anniversary  of the Change of  Control,  a
supplemental  amount in a lump sum equal to 50% of your  current Base Salary and
Bonuses paid during the preceding  fiscal year, and the fair market value of all
other benefits then payable,  irrespective  of whether you  thereafter  actually
terminate employment with the Company.

            (c) In   the  event  of  your  actual   termination   of  employment
contemporaneous  with or  following a Change in  Control,  except (x) because of
your death, (y) by the Company for Cause or Disability (as hereinafter  defined)
or (z) by you other than for Good Reason (as hereinafter defined): (i) you shall
be entitled to receive,  in lieu of the sums  described  in Section 6, an amount
equal to 100% of the Severance  Benefits due and  determined as if payable under
Section 6 above, for each full year or portion thereof you have been employed by
the  Company,  up to a maximum of 299% of the  severance  benefits  mentioned in
Section 6 above, to be paid in accordance with the terms of this Agreement;  and
(ii) the following additional provisions shall apply (which provisions


                                      A-3






shall supersede any other provisions of the Agreement, including but not limited
to Section 2 of the Agreement,  to the extent such  provisions are  inconsistent
with the following provisions):

                (1) Disability.  For purposes of this Section 7(c),  termination
by the Company of your employment  based on "Disability"  shall mean termination
because of your  absence  from your duties with the Company on a full time basis
for one hundred eighty (180) consecutive days as a result of your incapacity due
to physical or mental  illness,  unless  within thirty (30) days after Notice of
Termination (as hereinafter defined) is given to you following such absence, you
shall have returned to the full time performance of your duties.

                (2) Good Reason. Termination by you of your employment for "Good
Reason" shall mean termination based on:

                    (A) a  determination  by you, in your  reasonable  judgment,
that there has been a material  adverse  change in your status or position(s) as
an executive officer of the Company as in effect immediately prior to the Change
in Control,  including,  without  limitation,  a material adverse change in your
status  or   position   as  a  result  of  a   diminution   in  your  duties  or
responsibilities   (other  than,  if  applicable,   any  such  change   directly
attributable  to the fact that the Company is no longer  publicly  owned) or the
assignment to you of any duties or responsibilities  which are inconsistent with
such  status or  position(s),  or any  removal  of you from,  or any  failure to
reappoint or reelect you to, such  position(s)  (except in  connection  with the
termination  of your  employment  for Cause or Disability or as a result of your
death or by you other than for Good Reason) and further  provided  that you have
given the Company  notice of this  material  adverse  change and the Company has
failed to correct such material  adverse  change  within a reasonable  period of
time (but at least 14 days after written notice from you);

                    (B) a reduction by the Company (within three years following
the Change of Control) in your Base Salary as in effect immediately prior to the
Change in Control;

                    (C) the failure by the Company (within three years following
the Change of Control) to continue in effect any Plan (as  hereinafter  defined)
in which  you are  participating  at the time of the  Change in  Control  of the
Company (or Plans providing you with at least  substantially  similar  benefits)
other than as a result of the normal  expiration  of any such Plan in accordance
with its terms as in effect at the time of the Change in Control,  or the taking
of any  action,  or the failure to act,  by the  Company  which would  adversely
affect  your  continued  participation  in any of  such  Plans  on at  least  as
favorable  a basis to you as is the case on the date of the Change in Control or
which  would  materially  reduce your  benefits in the future  under any of such
Plans or deprive you of any material  benefit  enjoyed by you at the time of the
Change in Control;

                    (D) the  failure by the  Company  to provide  and credit you
with the  number  of paid  vacation  days to  which  you are  then  entitled  in
accordance with the Company's  normal  vacation policy as in effect  immediately
prior to the Change in Control;


                                      A-4







                    (E) the  Company's  requiring  you to be based at any office
that is greater  than  twenty  (20)  miles  from  where  your  office is located
immediately  prior to the Change in Control  except for  required  travel on the
Company's  business  to an extent  substantially  consistent  with the  business
travel  obligations  which you  undertook on behalf of the Company  prior to the
Change in Control;

                    (F) the failure by the Company to obtain from any  Successor
(as  hereinafter  defined) the assent to this Agreement  contemplated by Section
7(c)(7) hereof; or

                    (G)  any  purported  termination  by  the  Company  of  your
employment which is not effected pursuant to a Notice of Termination  satisfying
the  requirements of Section 7(c)(4) below (and, if applicable,  Section 7(c)(1)
above); and for purposes of this Agreement,  no such purported termination shall
be effective.

         For purposes of this Agreement, "Plan" shall mean any compensation plan
or any employee benefit plan such as a thrift, pension, profit sharing, medical,
disability,  accident, life insurance plan or a relocation plan or policy or any
other plan, program or policy of the Company intended to benefit employees.

                (3) [INTENTIONALLY LEFT BLANK]

                (4) Notice of  Termination.  Any  purported  termination  by the
Company or by you following a Change in Control shall be communicated by written
notice to the other  party  hereto  which  indicates  the  specific  termination
provision in this Agreement relied upon (the "Notice of Termination").

                (5) Date of  Termination.  "Date  of  Termination"  following  a
Change in Control  shall mean (A) if your  employment  is to be  terminated  for
Disability, thirty (30) days after Notice of Termination is given (provided that
you shall not have  returned  to the  performance  of your duties on a full-time
basis  during such  thirty (30) day  period),  (B) if your  employment  is to be
terminated  by the Company for any reason other than death or  Disability  or by
you  pursuant to  Sections  7(c)(2)(F)  or 7(c)(7)  hereof or for any other Good
Reason,  the  date  specified  in the  Notice  of  Termination,  or (C) if  your
employment is terminated on account of your death,  the day after your death. In
the case of termination of your employment by the Company for Cause, if you have
not  previously  expressly  agreed in writing to the  termination,  then  within
thirty (30) days after receipt by you of the Notice of Termination  with respect
thereto,  you may  notify  the  Company  that a dispute  exists  concerning  the
Termination, in which event the Date of Termination shall be the date set either
by mutual written agreement of the parties or by arbitration as described in '17
of the Agreement.


                                      A-5







                (6) Compensation  Upon Termination or During  Disability;  Other
Agreements.

                    (A) During any period  following  a Change in Control of the
Company  that you fail to perform your duties as a result of  incapacity  due to
physical or mental  illness,  you shall  continue to receive your Base Salary at
the rate then in effect and any benefits or awards under any Plan shall continue
to accrue during such period,  to the extent not  inconsistent  with such Plans,
until and unless your  employment  is  terminated  pursuant to and in accordance
with this  Section  7(c).  Thereafter,  your  benefits  shall be  determined  in
accordance with the Plans then in effect.

                    (B) If your  employment is terminated for Cause  following a
Change in Control of the Company,  the Company shall pay to you your Base Salary
through the Date of  Termination  at the rate in effect just prior to the time a
Notice of Termination is given plus any benefits or awards  (including  both the
cash and stock  components)  which  pursuant to the terms of any Plans have been
earned or become  payable,  but which have not yet been paid to you.  Thereupon,
the Company shall have no further obligations to you under this Agreement.

                (7) Successors, Binding Agreement.

                    (A) The Company will seek, by written  request at least five
(5) business days prior to the time a Person becomes a Successor (as hereinafter
defined),  to have such Person, by agreement in form and substance  satisfactory
to you,  assent to the  fulfillment  of the  Company's  obligations  under  this
Agreement.  Failure of such  Person to furnish  such  assent by the later of (i)
three (3)  business  days prior to the time such Person  becomes a Successor  or
(ii) two (2) business  days after such Person  receives a written  request to so
assent shall constitute Good Reason for termination by you of your employment if
a Change in Control of the Company occurs or has occurred.  For purposes of this
Section 7 of Exhibit A,  "Successor"  shall mean any person that succeeds to, or
has the practical ability to control, the Company's business directly, by merger
or  consolidation,  or  indirectly,  by  purchase  of the  Company's  securities
eligible to vote for the election of directors, or otherwise.

                    (B) This  Agreement  shall  inure to the  benefit  of and be
enforceable by your personal legal representatives,  executors,  administrators,
successors, heirs, distributees,  devisees and legatees. If you should die while
any amount would still be payable to you hereunder if you had continued to live,
all such amounts,  unless otherwise provided herein, shall be paid in accordance
with the terms of this Agreement to your devisee,  legatee or other designee or,
if no such designee exists, to your estate.

                    (C) For  purposes  of this  Section 7, the  "Company"  shall
include any  subsidiaries  of the Company and any  corporation  or other  entity
which  is  the  surviving  or  continuing  entity  in  respect  of  any  merger,
consolidation  or form of business  combination  in which the Company  ceases to
exist;  provided,  however,  for  purposes  of  determining  whether a Change in


                                       A-6






Control has occurred  herein,  the term "Company" shall refer to Applied Science
and Technology, Inc. or its Successor(s).

                (8) Fees and Expenses; Mitigation.

                    (A) The Company shall reimburse you, on a current basis, for
all  reasonable  legal fees and related  expenses  incurred by you in connection
with the  Agreement  following  a Change in  Control of the  Company,  including
without  limitation,  (i) all  such  fees  and  expenses,  if any,  incurred  in
contesting or disputing any  termination of your employment or (ii) your seeking
to obtain or enforce any right or benefit  provided by this  Agreement,  in each
case,  regardless of whether or not your claim is upheld by a court of competent
jurisdiction; provided, however, you shall be required to repay any such amounts
to the  Company to the  extent  that a court  issues a final and  non-appealable
order  setting  forth  the  determination  that  the  position  taken by you was
frivolous or advanced by you in bad faith.

                    (B) You shall not be required to mitigate  the amount of any
payment the Company  becomes  obligated to make to you in  connection  with this
Agreement, by seeking other employment or otherwise.

                (9) Taxes.  All payments to be made to you under this  Agreement
will be subject to required  withholding of federal,  state and local income and
employment taxes.

            (d)  Notwithstanding  any other provision of this Agreement,  in the
event that any payment or benefit  received or to be received by you as a result
of or in connection with a Change in Control,  whether  pursuant to the terms of
this Agreement or any other plan, arrangement or agreement with the Company (all
such payment and benefits being  hereinafter  called the "Total Payments") would
subject you to the excise tax (the "Excise  Tax")  imposed under Section 4999 of
the Internal Revenue Code of 1986, as amended (the "Code"),  then, to the extent
necessary to eliminate any such  imposition of the Excise Tax (after taking into
account any reduction in the Total Payments in accordance with the provisions of
any other plan,  arrangement or agreement,  if any), (a) any non-cash  severance
payments  otherwise  payable to you shall  first be reduced  (if  necessary,  to
zero), and (b) any cash severance payment otherwise payable to you shall next be
reduced. For purposes of the immediately  preceding sentence,  (i) no portion of
the Total Payments the receipt or enjoyment of which you shall have  effectively
waived in  writing  shall be taken  into  account,  (ii) no portion of the Total
Payment    shall   be   taken   into   account   which   in   the   opinion   of
nationally-recognized  certified  public  accountants  (in each case as mutually
selected by you and the  Company)  does not  constitute  a  "parachute  payment"
within the meaning of Section 280G of the Code,  including,  without limitation,
by reason of Section  280G(b)(2) or (b)(4)(A) of the Code, (iii) any payments to
you shall be reduced  only to the extent  necessary  so that the Total  Payments
[other  than  those  referred  to in  clauses  (i) and  (ii)] in their  entirety
constitute  reasonable  compensation for services  actually  rendered within the
meaning  of  section  280G(4)(B)  of the Code or are  otherwise  not  subject to
disallowance as deductions, in the opinion of the tax counsel or the accountants
referred to in clause (ii);  and (iv) the value of any  non-cash  benefit or any
deferred  payment


                                      A-7






or  benefit  included  in  the  Total  Payments  shall  be  determined  by  such
accountants in accordance with the requirements of section 280G(d)(3) and (4) of
the Code (and such determination shall be reviewed by such tax counsel).

         8. Expenses. The Company shall reimburse you for all usual and ordinary
business expenses incurred by you in the scope of your employment hereunder.

         9. Stock  Options.  You shall be entitled to receive  stock  options to
purchase  up to an  aggregate  of 50,000  shares of common  stock of the Company
issuable  as  follows:  options  to  purchase  30,000  shares  upon the date you
commence employment with the Company and up to an additional 20,000 shares under
options  which may be issued by the Company on July 1, 1997 and/or July 1, 1998.
These options shall vest in accordance with the Company=s  normal vesting policy
for stock option grants.










                                       A-8








                                                                       EXHIBIT B






                    OUTSIDE EMPLOYMENTS AND DIRECTORSHIPS OF

                                BRIAN R. CHISHOLM



                                      None







                                      B-1











                                      
                                                                       EXHIBIT C



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

               PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT

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

To:      Applied Science and Technology, Inc.
         35 Cabot Road
         Woburn, Massachusetts  01801

                                                         As of November 26, 1996

         The  undersigned,  in  consideration  of  and  as  a  condition  of  my
employment  or continued  employment  by you and/or by companies  which you own,
control,  or are affiliated with or their successors in business  (collectively,
the "Company"), hereby agrees as follows:

         1. Confidentiality. I agree to keep confidential, except as the Company
may otherwise consent in writing,  and, except for the Company's benefit, not to
disclose  or make any use of at any  time  either  during  or  subsequent  to my
employment, any Inventions (as hereinafter defined), trade secrets, confidential
information,  knowledge,  data or other  information of the Company  relating to
products,  processes,  know-how,  designs,  formulas, test data, customer lists,
business plans,  marketing plans and strategies,  pricing  strategies,  or other
subject  matter  pertaining  to  any  business  of  the  Company  or  any of its
affiliates,  which I may produce, obtain, or otherwise acquire during the course
of my  employment,  except as herein  provided.  I further agree not to deliver,
reproduce or in any way allow any such trade secrets,  confidential information,
knowledge, data or other information,  or any documentation relating thereto, to
be  delivered  to or used by any third  parties  without  specific  direction or
consent of a duly authorized representative of the Company.

         2. Conflicting  Employment;  Return of Confidential  Material.  I agree
that  during  my  employment  with the  Company  I will not  engage in any other
employment, occupation, consulting or other activity relating to the business in
which  the  Company  is now or may  hereafter  become  engaged,  or which  would
otherwise  conflict  with  my  obligations  to  the  Company.  In the  event  my
employment  with the Company  terminates for any reason  whatsoever,  I agree to
promptly surrender and deliver to the Company all records, materials, equipment,
drawings,  documents and data of which I may obtain or produce during the course
of my  employment,  and I will not take with me any  description  containing  or
pertaining  to any  confidential  information,  knowledge or data of the Company
which I may produce or obtain during the course of my employment.



                                      C-1





         3. Assignment of Inventions.

            3.1 I hereby  acknowledge and agree that the Company is the owner of
all Inventions.  In order to protect the Company's rights to such Inventions, by
executing  this  Agreement  I hereby  irrevocably  assign to the  Company all my
right, title and interest in and to all Inventions to the Company.

            3.2 For  purposes  of this  Agreement,  "Inventions"  shall mean all
discoveries,  processes, designs, technologies,  devices, or improvements in any
of the foregoing or other ideas,  whether or not  patentable  and whether or not
reduced to practice,  made or  conceived  by me (whether  solely or jointly with
others) during the period of my employment  with the Company which relate in any
manner to the actual or demonstrably anticipated business, work, or research and
development of the Company, or result from or are suggested by any task assigned
to me or any work performed by me for or on behalf of the Company.

            3.3  Any  discovery,   process,  design,   technology,   device,  or
improvement  in any of the foregoing or other ideas,  whether or not  patentable
and whether or not reduced to practice,  made or conceived by me (whether solely
or jointly with others) which I develop entirely on my own time not using any of
the  Company's  equipment,  supplies,  facilities,  or trade secret  information
("Personal  Invention") is excluded from this  Agreement  provided such Personal
Invention  (a)  does  not  relate  to the  actual  or  demonstrably  anticipated
business,  research and  development  of the  Company,  and (b) does not result,
directly or indirectly, from any work performed by me for the Company.

         4.  Disclosure  of  Inventions.  I agree  that in  connection  with any
Invention,  I will promptly disclose such Invention to my immediate  superior at
the  Company in order to permit the Company to enforce  its  property  rights to
such  Invention  in  accordance  with this  Agreement.  My  disclosure  shall be
received in confidence by the Company.

         5. Patents and Copyrights; Execution of Documents.

            5.1 Upon  request,  I agree to assist the Company or its nominee (at
its  expense)  during  and at any  time  subsequent  to my  employment  in every
reasonable  way to  obtain  for its  own  benefit  patents  and  copyrights  for
Inventions in any and all countries.  Such patents and  copyrights  shall be and
remain the sole and exclusive property of the Company or its nominee. I agree to
perform  such lawful acts as the Company  deems to be  necessary  to allow it to
exercise all right, title and interest in and to such patents and copyrights.

            5.2  In  connection  with  this  Agreement,   I  agree  to  execute,
acknowledge  and deliver to the Company or its nominee  upon  request and at its
expense all  documents,  including  assignments  of title,  patent or  copyright
applications,  assignments  of such  applications,  assignments  of  patents  or
copyrights upon issuance, as the Company may determine necessary or desirable to


                                      C-2








protect the Company's or its nominee's interest in Inventions,  and/or to use in
obtaining  patents  or  copyrights  in any and all  countries  and to vest title
thereto in the Company or its nominee to any of the foregoing.
      
         6. Maintenance of Records.   I agree to keep and maintain  adequate and
current  written  records  of all  Inventions  made by me (in the form of notes,
sketches,  drawings and other records as may be specified by the Company), which
records shall be available to and remain the sole property of the Company at all
times.

         7. Prior Inventions.  It is understood that all Personal Inventions, if
any, whether patented or unpatented,  which I made prior to my employment by the
Company, are excluded from this Agreement. To preclude any possible uncertainty,
I have set forth on  Schedule  A attached  hereto a  complete  list of all of my
prior  Personal  Inventions,   including  numbers  of  all  patents  and  patent
applications and a brief description of all unpatented Personal Inventions which
are not the property of a previous  employer.  I represent and covenant that the
list is  complete  and that,  if no items are on the list,  I have no such prior
Personal Inventions.  I agree to notify the Company in writing before I make any
disclosure  or  perform  any work on  behalf of the  Company  which  appears  to
threaten or conflict with proprietary rights I claim in any Personal  Invention.
In the event of my  failure  to give such  notice,  I agree  that I will make no
claim against the Company with respect to any such Personal Invention.

         8. Other Obligations.  I acknowledge that the Company from time to time
may have agreements  with other persons or with the U.S.  Government or agencies
thereof,  which impose  obligations  or  restrictions  on the Company  regarding
Inventions   made  during  the  course  of  work  thereunder  or  regarding  the
confidential  nature of such work.  I agree to be bound by all such  obligations
and  restrictions  and to take all action  necessary to discharge  the Company's
obligations.

         9. Trade Secrets of Others.  I represent that my performance of all the
terms of this  Agreement and as an employee of the Company does not and will not
breach any agreement to keep confidential proprietary information,  knowledge or
data acquired by me in  confidence  or in trust prior to my employment  with the
Company,  and I will not disclose to the Company,  or induce the Company to use,
any  confidential  or  proprietary  information  or  material  belonging  to any
previous  employer  or others.  I agree not to enter into any  agreement  either
written or oral in conflict herewith.

         10.  Modification.  I agree that any subsequent change or changes in my
employment duties,  salary or compensation or, if applicable,  in any Employment
Agreement  between the Company and me, shall not affect the validity or scope of
this Agreement.

         11.  Successors and Assigns.  This  Agreement  shall be binding upon my
heirs,  executors,  administrators or other legal representatives and is for the
benefit of the Company, its successors and assigns.


                                      C-3








         12. Interpretation.   IT IS THE INTENT OF THE PARTIES  THAT in case any
one or more of the provisions contained in this Agreement shall, for any reason,
be held to be invalid, illegal or unenforceable in any respect, such invalidity,
illegality  or  unenforceability  shall not affect the other  provisions of this
Agreement,  and this Agreement shall be construed as if such invalid, illegal or
unenforceable  provision had never been contained  herein.  MOREOVER,  IT IS THE
INTENT OF THE PARTIES THAT in case any one or more of the  provisions  contained
in this  Agreement  shall for any reason be held to be  excessively  broad as to
duration,  geographical  scope,  activity or subject,  such  provision  shall be
construed by limiting and reducing it in  accordance  with a judgment of a court
of competent jurisdiction, so as to be enforceable to the extent compatible with
applicable law.

         13.  Waivers.  If either party should waive any breach of any provision
of this  Agreement,  he or it shall not  thereby  be deemed to have  waived  any
preceding  or  succeeding  breach  of the same or any  other  provision  of this
Agreement.

         14.  Complete  Agreement,  Amendments.  I  acknowledge  receipt of this
Agreement,  and agree that with respect to the subject  matter  thereof it is my
entire  agreement  with the Company,  superseding  any previous  oral or written
communications, representations,  understandings, or agreements with the Company
or any officer or  representative  thereof.  Any amendment to this  Agreement or
waiver  by  either  party of any  right  hereunder  shall be  effective  only if
evidenced by a written  instrument  executed by the parties hereto,  and, in the
case of the  Company,  upon  written  authorization  of the  Company's  Board of
Directors.

         15.  Headings.  The  headings of the  sections  hereof are inserted for
convenience  only and shall not be deemed to  constitute  a part  hereof  nor to
affect the meaning thereof.

         16.  Counterparts.  This  Agreement may be signed in two  counterparts,
each of which  shall be  deemed an  original  and both of which  shall  together
constitute one agreement.

         17. Governing Law. This Agreement shall be governed and construed under
Massachusetts law.

         18 Employment  Status.  Nothing in this  Agreement  shall affect in any
manner  whatsoever the right or power of the Company to terminate the employment
of the Employee.

                                       EMPLOYEE


                                       ------------------------------------
                                       Brian R. Chisholm
Accepted and Agreed:
APPLIED SCIENCE AND TECHNOLOGY,  INC.


By:
   -----------------------------------
      Dr. Richard S. Post, President


                                      C-4






                                                                     SCHEDULE A



                            LIST OF PRIOR INVENTIONS
                              OF BRIAN R. CHISHOLM



                                                         Identifying Number or
Title                      Date                             Brief Description
-----                      ----                             -----------------


                                    NONE



                                       C-5