JOINT VENTURE TERMINATION &
                           STOCK REDEMPTION AGREEMENT

                                     BETWEEN


                               AMTECH SYSTEMS, INC

                                       AND

                              INDIVIDUAL INVESTORS
                                       AND
                               SEIL SEMICON, INC.









                             DATED: September , 1996
<PAGE>
                           JOINT VENTURE TERMINATION &
                           STOCK REDEMPTION AGREEMENT

                                     BETWEEN


                               AMTECH SYSTEMS, INC

                                       AND

                              INDIVIDUAL INVESTORS
                                       AND
                               SEIL SEMICON, INC.



         The parties to this Agreement are Amtech Systems,  Inc.  ("Amtech"),  a
corporation  duly organized and existing under the laws of the State of Arizona,
United States of America  ("USA") having its principal  place of business at 131
South  Clark  Drive,  Tempe,  Arizona,  USA,  the  INDIVIDUAL  INVESTORS,  whose
signatures are subscribed hereto, being hereinafter  collectively referred to as
the KOREAN  INVESTMENT  GROUP  ("KIG"),  and Seil Semicon,  Inc., a Korean joint
stock company (chusik hoesa) ("Seil").

The parties have agreed as follows:

1.       RECITALS

         1.1  Stock  Ownership.  Amtech is the  owner of 45% of the  issued  and
outstanding  capital  stock  of Seil and has the  proxy  of A.G.  Lee to vote an
additional 5% of the outstanding capital stock of Seil. Furthermore, Amtech is a
joint venture partner in Seil, with the second largest  interest in the venture,
through the Joint Venture Agreement dated September 30, 1995, as revised per the
Amendment  Agreement dated November 23, 1995, and through which certain benefits
and obligations were to accrue to Amtech (the "JVC AGREEMENT").

         1.2 Purpose. The KIG has requested the termination of the JVC Agreement
and has sought mutual agreement for termination pursuant to Article 17.1 of that
agreement.  Amtech has agreed to said  termination  on the condition that mutual
agreement is reached for the  disposition  of its  interest in Seil  pursuant to
Article  18.2 of the JVC  Agreement.  Seil  desires to redeem the 45%  ownership
interest  of Seil owned by Amtech  through  the  purchase  from it of all of the
outstanding  capital stock of Seil owned by Amtech ("Seil Stock"), in accordance
with the mutual  agreement  reached between the KIG,  Amtech,  and Seil.  Amtech
desires to sell the Seil Stock to Seil  pursuant to the terms and  conditions of
this Agreement.

2.       THE TRANSACTION

         2.1  Redemption  of  Seil  Stock.  Subject  to  all of  the  terms  and
conditions of this Agreement, Amtech agrees to sell and Seil
                                        2
<PAGE>
agrees to redeem,  at the Closing  (hereinbelow  defined),  but  effective as of
September 30, 1996, unless closed earlier, the Seil Stock, free and clear of all
liens, claims, options, charges and encumbrances whatsoever,  for the redemption
price specified below.

         2.2 Redemption  Price. The redemption price for the Seil Stock shall be
$478,143 and shall be paid on or before September 30, 1996.

         2.3 Termination of JVC. When one or more Certificates of Termination in
the same form as Exhibit A, attached,  have been signed by Amtech, Seil, and the
KIG, Mr. Seung Kag Hong, Jae-Im Ko, his wife, and A.G. Lee (the "Parties"),  the
JVC will  terminate  and the Parties  will no longer have any further  rights or
obligations  under  the  JVC  Agreement,  except  as  may  be  provided  in  the
Certificates of Termination.

         2.4  Closing.  The  delivery  of the Seil  Stock,  the  delivery of the
Certificates  of  Termination,  and the payment of the  redemption  price in the
amount of $478,143 and of any other  instruments,  certificates  and items to be
delivered  under this  Agreement (the  "Closing")  shall take place by facsimile
assignment  of  the  Seil  Stock,  facsimile  delivery  of the  Certificates  of
Termination and the wire transfer, with facsimile confirmation, of funds via the
SWIFT system to:

                           Mellon Bank
                           Pittsburgh, Pennsylvania, USA
                           ABA # 0430-0026-1
                           Credit:  Merrill Lynch
                           For further credit to:
                           Amtech Systems, Inc.

on or before  September 30, 1996,  Arizona time (the "closing  Date") or at such
other place or time upon which the  parties  may agree in  writing.  The Parties
hereby  agree  that  signed  assignments,  certificates  and  other  instruments
delivered by means of facsimile transmission will be legally binding and treated
the same as if an original.  Facsimile transmissions to Amtech should be sent to
1-602-968-3763 and if to any of the other Parties to 82-2-581-4773.  The Parties
agree to mail a signed  original of each  document  delivered by  facsimile,  if
requested by one of the other Parties.

3.   REPRESENTATIONS AND WARRANTIES OF AMTECH

         3.1. Representations and Warranties.  Amtech represents and warrants to
and agrees with Seil that:

                  (a) Authority.  Amtech has all requisite  corporate  power and
         authority to execute, deliver and perform this Agreement
                                        3
<PAGE>
         and  has  taken  all  necessary   corporate  action  to  authorize  the
         execution, delivery and performance of this Agreement and to consummate
         the  transactions  contemplated by this  Agreement.  This Agreement has
         been duly  executed  and  delivered  by Amtech,  and each  document  or
         instrument  executed or to be executed by Amtech  pursuant  hereto upon
         execution and delivery will have been duly executed and delivered,  and
         this Agreement  constitutes the legal,  valid and binding obligation of
         Amtech, enforceable in accordance with its terms.

                  (b) No Conflict. The execution and delivery of this Agreement,
         the  consummation  of the  transactions  contemplated  hereby,  and the
         compliance  with the  terms and  conditions  hereof  will  not,  to the
         knowledge of Amtech,  conflict  with,  or result in a breach of (1) any
         relevant  statute,  law,  ordinance,  rule or regulation  applicable to
         Amtech or its business,  or (2) the terms,  conditions or provisions of
         the corporate charter or the by-laws of Amtech,  the conflict or breach
         of which would adversely affect Seil's rights hereunder in any material
         respect.


                  (c) Disclosure.  To the knowledge of Amtech, no representation
         or warranty  by Amtech  hereunder  contains or will  contain any untrue
         statement of a material fact, or omits or will omit to state a material
         fact necessary to make the statements contained therein not misleading.


         3.2.  Representations  and Warranties  True on the Closing Date. To the
knowledge  of  Amtech,  all of the  representations  and  warranties  of  Amtech
contained herein shall be true and correct in all material respects on and as of
the Closing  Date,  except as  consented  to by Seil in writing on or before the
Closing Date.

         3.3. Survival of Representations  and Warranties.  The  representations
and warranties of Amtech contained herein shall survive the Closing Date.

4.   REPRESENTATIONS AND WARRANTIES OF SEIL AND KIG

         4.1.   Representations   and  Warranties.   Seil  and  the  undersigned
Individual Investors represent and warrant to and agree with Amtech that:

                  (a) Corporate Existence.  Seil is a corporation duly organized
         and existing  under the laws of Korea and has the  corporate  power and
         authority to enter into this Agreement.

                  (b) Validity of Agreement. Seil has taken such corporate steps
         as are  necessary to authorize  the  execution of the  Agreement and to
         comply in full with the terms thereof
                                        4
<PAGE>
         that are to be performed by Seil. This Agreement is a valid  obligation
         of Seil in accordance  with its terms.  This  Agreement and  compliance
         with  its  terms  are  not   inconsistent   with  Seil's   Articles  of
         Organization, its by-laws or any agreement to which Seil is a party.

         This  Agreement  when signed by the  Individual  Investors will binding
         upon them.

                  (c)  Governmental   Interference.   Seil  and  the  Individual
         Investors do not know or have reasonable  grounds to know of any action
         before a court or other  governmental body pending or threatened by the
         government or any agency thereof or by any other third party that might
         restrain or prohibit the redemption by Seil of the Seil Stock as herein
         contemplated or the termination of the JVC Agreement.

                  (d) Consents and Approvals.  Seil and the Individual Investors
         do not know or have  reasonable  grounds to know of any requirement for
         the  consents  or  approvals  of  third  parties,  whether  they be the
         Industrial Bank of Korea, its affiliates,  parties to other agreements,
         or the government of Korea or its provinces or any agency  thereof,  in
         order to enter into the  Agreement and to comply in full with the terms
         thereof that are to be performed by them,  or that if any such consents
         or approvals are so required, they will be obtained by the Closing.


         4.2.  Representations  and Warranties  True on Closing Date. All of the
representations  and warranties of Seil and the Individual  Investors  contained
herein shall be true and correct in all respects on and as of the Closing  Date,
except as consented to by Amtech on or before the Closing.


5.   CONDITIONS TO CLOSING

         5.1.  Conditions to Closing by the Parties.  The obligations of Amtech,
KIG and Seil to  consummate  the  transactions  contemplated  hereby are, at the
option of each party,  subject to the  fulfillment  of the condition that on the
Closing Date:

                  (a)  there  shall  not be any  injunction,  writ,  preliminary
         restraining  order or any  order of any  nature  issued by any court or
         governmental  agency  directing the  transaction  contemplated  by this
         Agreement not be consummated, and

                  (b) there shall not be pending or known to be  threatened  any
         action,   proceeding  or   investigation   before  any  such  court  or
         governmental agency seeking as to any party hereto any such injunction,
         writ, or preliminary restraining order.
                                        5
<PAGE>
         5.2. Conditions to Closing by Seil and the KIG. The obligations of Seil
and the KIG to  consummate  the  transactions  contemplated  hereby  are, at the
option of Seung Kag Hong,  subject to the  fulfillment of each of the conditions
that, on or before the Closing Date:

                  (a)   Representations   and   Warranties   True;   Obligations
         Performed.

                           (i) The  representations  and  warranties  of  Amtech
                  contained  in Section 3.1 hereof  shall be true and correct in
                  all material respects at and as of the Closing Date except for
                  specifically consented to or approved by Seil in writing, with
                  the same force and effect as if made at and as of the  Closing
                  Date;

                           (ii)  Amtech   shall  have   delivered   to  Seil  an
                  assignment of the Seil Stock or other documents reflecting the
                  legal  transfer of ownership as may reasonably be requested by
                  Seil,  dated the Closing  Date and signed by the  President of
                  Amtech.


                  (c)  Certain   Legal   Matters.   All  actions,   proceedings,
         instruments  and  documents  required to carry out this  Agreement,  or
         incidental  thereto,  and all other  related  legal  matters,  shall be
         reasonable  satisfactory  to the  President  of or counsel for Seil and
         such person shall have received all  documents,  instruments  or copies
         thereof, certified if and as may be reasonably requested.

                  (d)  Compliance.  Amtech shall have  performed and complied in
         all material  respects with all  agreements,  covenants and  conditions
         required by this  Agreement  to have been  performed  or complied  with
         prior to or at the Closing Date.

                  (e) Other Instruments and Actions.  Amtech shall have executed
         and  delivered  to Seil such  other  instruments  and taken  such other
         action  as Seil may  reasonably  have  requested  with  respect  to the
         transactions contemplated by this Agreement.

         5.3  Conditions  to  Closing by Amtech.  The  obligations  of Amtech to
consummate the  transactions  contemplated  hereby are, at the option of Amtech,
subject to the  fulfillment  of each of the  conditions  that,  on or before the
Closing Date:

                  (a)   Representations   and   Warranties   True;   Obligations
         Performed.  (i) The  representations  and  warranties  of Seil  and the
         Individual  Investors contained in Section 4.1 hereof shall be true and
         correct at and as of the Closing Date except
                                        6
<PAGE>
         for  specifically  consented to or approved by Amtech in writing,  with
         the same force and effect as if made at and as of the Closing Date.

                  (b)  Compliance.  Seil and the KIG shall  have  performed  and
         complied with all agreements, covenants and conditions required by this
         Agreement to have been  performed  or complied  with prior to or at the
         Closing Date.

6.       BROKERS

         Amtech  and Seil  represent  that  they  have  dealt  with no broker in
connection with any of the transactions  contemplated by this Agreement and that
no broker or other  person is entitled  to any  commission  or  finder's  fee in
connection with any of such transactions.


7.       INDEMNIFICATION BY AMTECH

         Amtech  hereby  agrees  to  indemnify  and hold  harmless  Seil and KIG
(herein  referred  to as  "Seil/KIG"),  at all  times  after  the  date  of this
Agreement, against and in respect of:

                  (a)  Any and all  damage  or  deficiency  resulting  from  any
         material  inaccuracy  of any  representation  or  warranty  made  by or
         non-fulfillment  of any  agreement  on the part of  Amtech  under  this
         Agreement,  whether  or not such  inaccuracy,  breach,  nonfulfillment,
         misrepresentation or omission was or should have been known by Seil/KIG
         on the date of this  Agreement,  it being the agreed  intention  of the
         parties that Amtech shall be completely  responsible  for, and Seil/KIG
         shall be conclusively deemed to have relied upon, such representations,
         warranties, agreements and instruments.

                  (b)  Any  and  all  actions,  suits,   proceedings,   demands,
         assessments,   judgments,   costs  and  expenses,   including   without
         limitation,   reasonable  attorneys'  fees,  incident  to  any  of  the
         foregoing;  provided  that no claim for  indemnification  shall be made
         pursuant to this  Section 7 unless  Seil/KIG  has  suffered  such loss,
         damage or expense in a cumulative minimum of $5,000.

                  (c) Promptly after receipt by Seil/KIG under this Section 7 of
         notice of the commencement of any action,  Seil/KIG will, if a claim in
         respect  thereof is to be made  against  Amtech  under this  Section 7,
         notify Amtech in writing of the commencement  thereof, but the omission
         to notify Amtech will not relieve Amtech from any liability that it may
         have to Seil/KIG  otherwise than under this Section 7. In case any such
         action  is  brought  against  Seil/KIG  and it  notifies  Amtech of the
         commencement thereof, Amtech will be entitled to
                                        7
<PAGE>
         participate  therein  and,  to the extent  that it may elect by written
         notice  delivered to Seil/KIG  promptly  after  receiving the aforesaid
         notice from Seil/KIG, to assume the defense thereof; provided, however,
         if the  defendants in any such action  include both Seil/KIG and Amtech
         and either (i) Amtech mutually agrees,  or (ii)  representation of both
         Seil/KIG  and  Amtech by the same  counsel is  inappropriate  under the
         applicable standards of professional conduct due to actual or potential
         conflicting  interests  between them,  Seil/KIG shall have the right to
         select separate  counsel to assume such legal defenses and to otherwise
         participate in the defense of such action. Amtech will not be liable to
         Seil/KIG  under  this  Section  7  for  any  legal  or  other  expenses
         subsequently  incurred  by  Seil/KIG  in  connection  with the  defense
         thereof unless (i) Seil/KIG  shall have employed  counsel in connection
         with the assumption of legal defenses in accordance with the proviso to
         the next preceding sentence (it being understood,  however, that Amtech
         shall not be liable for the expense of more than one  separate  counsel
         approved by Amtech),  (ii) Amtech  shall not have  employed  counsel to
         represent   Seil/KIG   within  a   reasonable   time  after  notice  of
         commencement  of  the  action,  or  (iii)  Amtech  has  authorized  the
         employment  of counsel for  Seil/KIG  at the  expense of Amtech.  In no
         event shall Amtech be liable  under this  Section 7 for any  settlement
         effected  without its written  consent,  of any claim or action against
         Seil/KIG.

8.       INDEMNIFICATION BY SEIL AND KIG

         Seil and the KIG (herein  referred to as  "Seil/KIG")  hereby  agree to
indemnify  and hold  harmless  Amtech and to accept joint and several  liability
therefor, at all times after the date of this Agreement,  against and in respect
of:

                  (a)  Any and all  damage  or  deficiency  resulting  from  any
         material  inaccuracy  of any  representation  or  warranty  made  by or
         non-fulfillment  of any  agreement  on the part of Seil/KIG  under this
         Agreement,  whether  or not such  inaccuracy,  breach,  nonfulfillment,
         misrepresentation  or omission  was or should have been known by Amtech
         on the date of this  Agreement,  it being the agreed  intention  of the
         parties that Seil/KIG shall be completely  responsible  for, and Amtech
         shall be conclusively deemed to have relied upon, such representations,
         warranties, agreements and instruments.

                  (c)  Any  and  all  actions,  suits,   proceedings,   demands,
         assessments,   judgments,   costs  and  expenses,   including   without
         limitation,   reasonable  attorneys'  fees,  incident  to  any  of  the
         foregoing;  provided  that no claim for  indemnification  shall be made
         pursuant to this Section 8 unless Amtech has suffered such loss, damage
         or expense in a cumulative minimum of $5,000.
                                        8
<PAGE>
                  (d) Promptly  after  receipt by Amtech under this Section 8 of
         notice of the  commencement  of any action,  Amtech will, if a claim in
         respect  thereof is to be made against  Seil/KIG  under this Section 8,
         notify  Seil/KIG  in  writing  of the  commencement  thereof,  but  the
         omission  to  notify  Seil/KIG  will  not  relieve  Seil/KIG  from  any
         liability that it may have to Amtech  otherwise than under this Section
         8. In case any such  action is brought  against  Amtech and it notifies
         Seil/KIG  of the  commencement  thereof,  Seil/KIG  will be entitled to
         participate  therein  and,  to the extent  that it may elect by written
         notice  delivered to Amtech  promptly  after  receiving  the  aforesaid
         notice from Amtech, to assume the defense thereof;  provided,  however,
         if the  defendants in any such action  include both Amtech and Seil/KIG
         and either (i) Seil/KIG mutually agrees, or (ii) representation of both
         Seil/KIG  and  Amtech by the same  counsel is  inappropriate  under the
         applicable standards of professional conduct due to actual or potential
         conflicting  interests  between  them,  Amtech  shall have the right to
         select separate  counsel to assume such legal defenses and to otherwise
         participate in the defense of such action.  Seil/KIG will not be liable
         to  Amtech  under  this  Section  8 for any  legal  or  other  expenses
         subsequently  incurred by Amtech in connection with the defense thereof
         unless (i) Amtech shall have employed  counsel in  connection  with the
         assumption of legal defenses in accordance with the proviso to the next
         preceding sentence (it being understood,  however,  that Seil/KIG shall
         not be  liable  for the  expense  of more  than  one  separate  counsel
         approved by Seil/KIG), (ii) Seil/KIG shall not have employed counsel to
         represent  Amtech within a reasonable time after notice of commencement
         of the action,  or (iii)  Seil/KIG has  authorized  the  employment  of
         counsel  for  Amtech at the  expense  of  Seil/KIG.  In no event  shall
         Seil/KIG be liable  under this  Section 8 for any  settlement  effected
         without its written consent, of any claim or action against Amtech.

9.       NOTICE

         Any and all notices herein provided for or relating to the transactions
contemplated  by this Agreement  shall be in writing and shall be deemed to have
been sufficiently given to Amtech if mailed,  postage prepaid, by certified mail
with return receipt requested and addressed to, or if delivered, to:


                              AMTECH SYSTEMS, INC.
                                 131 SOUTH CLARK
                              TEMPE, ARIZONA 85281
                           ATTN: J.S. WHANG, PRESIDENT

and to Seil if mailed,  postage  prepaid,  by certified mail with return receipt
requested and addressed to, or delivered, to:
                                        9
<PAGE>
                               SEIL SEMICON, INC.

                               SEOUL, SOUTH KOREA
                         ATTN: SEUNG KAG HONG, PRESIDENT


and to KIG if mailed,  postage  prepaid,  by certified  mail with return receipt
requested and addressed to, or delivered, to:

                             MR. SEUNG KAG HONG AND
                                    JAE-IM-KO
                                211-1402 LG APT.
                             JUNG-JA DONG, SUNG-NAM
                               KYUNG-KI DO, KOREA

or to such other address as either party may specify in writing by notice to the
other.

10.      EXPENSES

         Amtech and Seil shall each pay their own costs and expenses incurred in
connection  with the  preparation  of this Agreement and the carrying out of the
transactions contemplated hereby. However, transfer taxes on the transfer of the
Seil Stock, if any, shall be born by Seil.


11.      ENTIRE AGREEMENT; MODIFICATION OF AGREEMENT

         This Agreement  contains the entire agreement and  understanding of the
parties  hereto with respect to Seil's  redemption of Seil Stock from Amtech and
supersedes any other oral or written  agreements or understandings  with respect
thereto, which agreements or understandings, if any, are hereby terminated. This
Agreement  may not be  altered,  modified  or changed  in any manner  whatsoever
except by a writing signed by Amtech, Seil and KIG.

13.      SUCCESSORS AND ASSIGNS

         The terms of this Agreement  shall be binding upon, and the benefits of
this Agreement shall inure to, the successors and assigns of the parties hereto.
Seil  shall  have the right to assign  its  rights  and  obligations  under this
Agreement to replacement  investor;  provided,  however,  that Seil shall remain
liable with respect to its obligations hereunder.

14.      GOVERNING LAW; LEGAL PROCEEDINGS

         Notwithstanding  the  termination  of the JVC Agreement at the Closing,
the  dispute  resolution,  arbitration  and  governing  law  applicable  to this
Agreement  shall be as provided in Article 23 of the JVC  Agreement  as if fully
setforth herein. Furthermore, this
                                       10
<PAGE>
Agreement  is  written  in the  English  language  and  executed  in  three  (3)
counterparts,  each of which shall be deemed an original.  The English  language
text of this Agreement shall prevail over any translation thereof. Any provision
or clause  hereof  which shall be  invalidated  by virtue of the fact that it is
prohibited  by law  shall  be  ineffective  to the  extent  of such  illegality;
however, this shall in no way affect the remaining provisions of this Agreement,
and this Agreement  shall be interpreted as if such clause or provision were not
contained  herein,  unless  such  ineffective  provision  or clause  shall be so
significant  as to materially  affect the parties'  expectations  regarding this
Agreement.


15.      COUNTERPARTS

         This   Agreement   may  be  executed  and  delivered  in  a  number  of
counterparts,  each of  which,  when so  executed  and  delivered,  shall  be an
original and all of such counterparts shall together constitute one and the same
Agreement.

         IN WITNESS  WHEREOF,  the parties have duly executed this  Agreement on
the date first above written.



AMTECH, INC.                                SEIL SEMICON, INC.



By____________________________              By_________________________
  J. S. Whang, President& CEO                 Seung Kag Hong, President




INDIVIDUAL INVESTORS



By____________________________              By____________________________
  Mr. Seung Kag Hong                          Mr. A.G. Lee



By____________________________
  Jae-Im Ko
                                       11
<PAGE>
                                                                       EXHIBIT 1


                           CERTIFICATE OF TERMINATION




DATE:



Pursuant to the terms and  conditions in the Joint  Venture  Termination & Stock
Redemption  Agreement,  each  of  the  undersigned  does  hereby  agree  to  the
termination of the Joint Venture  Agreement dated September 30, 1995, as revised
per the Amendment Agreement dated November 23, 1995, and further agrees that all
rights and  obligations  arising  out of that  agreement  are  terminated.  This
Certificate of Termination  shall be effective when Amtech  Systems,  Inc., Seil
Semicon, Inc., Seung Kag Hong, Jae-Im Ko, his wife, and A.G. Lee have all signed
this  Certificate of Termination or another one with the same content and Amtech
has received the redemption price.

         IN WITNESS  WHEREOF,  the parties have duly executed this  Agreement on
the date first above written.


AMTECH, INC.                                   SEIL SEMICON, INC.


By____________________________                 By_________________________
  J. S. Whang, President & CEO                   Seung Kag Hong, President


INDIVIDUAL INVESTORS


By____________________________
  Mr. Seung Kag Hong



By____________________________
  Jae-Im Ko



By____________________________
  Mr. A.G. Lee