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                                                                   Exhibit 10.36


                          SECURITY AGREEMENT (PATENTS)


         WHEREAS, MICRION CORPORATION, a Massachusetts corporation, with a
principal place of business at One Corporation Way, Peabody, MA 01960 (the
"Company") and FLEET NATIONAL BANK, with a place of business at 75 State Street,
Boston, Massachusetts 02109 (the "Bank") have entered into an Inventory,
Accounts Receivable and Intangibles Security Agreement dated as of July 31, 1997
(the "Security Agreement") and are also parties to a related letter agreement
(the "Letter Agreement") between the Bank and the Company; and

         WHEREAS, the Company is the owner and user of the United States Patents
and Patent Applications listed on Schedule A hereto and identified in said
Security Agreement (collectively, the "U.S. Patents"); and

         WHEREAS, among the security interests granted by the Company to the
Bank pursuant to the Security Agreement is a security interest in the U.S.
Patents listed on Schedule A hereto; and

         WHEREAS, the parties to the Security Agreement contemplate and intend
that, if an Event of Default (as defined in the Letter Agreement) shall occur
and be continuing, the Bank shall have all rights of a foreclosing secured party
in and to the U.S. Patents and any proceeds thereof, including, without
limitation, t he right, following such foreclosure, to transfer to a purchaser
all of the Company's right, title and interest in and to the U.S. Patents;

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties reconfirm the terms of
the Security Agreement, as if set forth fully herein, and acknowledge that the
Bank has a security interest in the U.S. Patents listed on Schedule A hereto; as
security for the Obligations (as defined in the Security Agreement) the Company
hereby collaterally assigns to the Bank, and grants a security interest to the
Bank in and to, all of the Company's right, title and interest in and to said
U.S. Patents; the Company agrees that it will not sell or assign any of the U.S.
Patents without the prior written consent of the Bank; and the Company and the
Bank request that the Commissioner of Patents and Trademarks record this
document with respect to the U.S. Patents.

         The Company hereby appoints the Bank as the Company's attorney-in-fact
(with full power of substitution and resubstitution) with the power and
authority, after the occurrence and during the continuance of any Event of
Default (as defined in the Letter Agreement), to execute and deliver, in the
name and on behalf of the Company, and to cause the recording of all such
further assignments and other instruments as the Bank may deem necessary or
desirable in order to carry out the intent of the Security Agreement and this
Security Agreement (Patents). The Company agrees that all third parties may
conclusively rely on any such further assignment or other instrument, so
executed, delivered and recorded by the Bank (or the Bank's designee in
accordance with the terms hereof) and on the statements made therein.
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MICRION CORPORATION                         FLEET NATIONAL BANK


By:  David M. Hunter                        By:  Thomas W. Davies
     Name:  David M. Hunter                 Its SVP
     Title: Vice President, Finance
             and Administration


COMMONWEALTH OF MASSACHUSETTS   )
                                ) SS.
COUNTY OF ESSEX                 )

         Then personally appeared before me the above-named David M. Hunter, the
Vice President, Finance and Administration of Micrion Corporation, and stated
that he/she executed the foregoing instrument under the authority of said
corporation's Board of Directors and acknowledged the foregoing instrument to be
the free act and deed of said corporation.

         WITNESS my hand and seal this 31st day of July, 1997.



                                            Patricia V. Rozumek
                                            Notary Public

                                            My commission expires:  4/23/04


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