EXHIBIT 1.1

                     PLASMA & MATERIALS TECHNOLOGIES, INC.

                                  $75,000,000

                7-1/8% Convertible Subordinated Notes Due 2001

                              PURCHASE AGREEMENT


                                                              New York, New York
                                                                 October 1, 1996


Salomon Brothers Inc
Unterberg Harris
c/o Salomon Brothers Inc
Seven World Trade Center
New York, New York 10048

Dear Sirs:

          Plasma & Materials Technologies, Inc., a California corporation (the
"Company" or "PMT"), proposes to issue and sell to the parties named in Schedule
I hereto (the "Purchasers"), $75,000,000 principal amount of its 7-1/8%
Convertible Subordinated Notes due 2001 (the "Firm Securities").  The Securities
will be convertible into shares of Common Stock, no par value per share (the
"Common Stock"), of the Company at the conversion price set forth herein.  The
Company also proposes to grant to you an option to purchase up to $11,250,000
additional principal amount of such Notes to cover over-allotments, if any (the
"Option Securities" and, together with the Firm Securities, the "Securities").
The Securities are to be issued under an indenture (the "Indenture") to be dated
as of October 7, 1996, between the Company and U.S. Trust Company of California,
N.A., as trustee (the "Trustee").

          The sale of the Securities to you will be made without registration of
the Securities or the Common Stock issuable upon conversion thereof under the
Securities Act of 1933, as amended (the "Act"), in reliance upon the exemption
from the registration requirements of the Act provided by Section 4(2) thereof.
You have advised the Company that you will make an offering of the Securities
purchased by you hereunder in accordance with Section 4 hereof on the terms set
forth in the Final Memorandum (as defined below), as soon as you deem advisable
after this Agreement has been executed and delivered.

          In connection with the sale of the Securities, the Company has
prepared a preliminary offering memorandum, dated September 13, 1996 (the
"Preliminary Memorandum"), and a final offering memorandum, dated October 1,
1996 (the "Final Memorandum").  The Company has also prepared a final proxy
statement dated September 11, 1996, and supplement dated October 1, 1996 (the
"Final Proxy Statement"), to be delivered to

 
its shareholders in order to obtain shareholder approval of the Company's
acquisition of Electrotech Limited and Electrotech Equipments Limited
(collectively, "Electrotech") pursuant to the Share Purchase Agreement dated
July 17, 1996, as amended ("Share Purchase Agreement") among the Company,
Electrotech and the shareholders named therein, as well as certain other matters
described therein.  Each of the Preliminary Memorandum and the Final Memorandum
sets forth certain information concerning the Company, the Securities and the
Common Stock issuable upon conversion thereof.  The Company hereby confirms that
it has authorized the use of the Preliminary Memorandum and the Final Memorandum
in connection with the offering and resale by the Purchasers of the Securities.
Any references herein to the Preliminary Memorandum and the Final Memorandum
shall be deemed to include all exhibits thereto and all documents incorporated
by reference therein that were filed under the Securities Exchange Act of 1934,
as amended (the "Exchange Act"), on or before the date and time that this
Agreement is executed and delivered by the parties hereto (the "Execution
Time"), including but not limited to the Final Proxy Statement; and any
reference herein to the terms "amend", "amendment" or "supplement" with respect
to the Final Memorandum shall be deemed to refer to and include the filing of
any document under the Exchange Act after the Execution Time that is
incorporated by reference therein.

          The holders of the Securities or the Common Stock issuable upon
conversion thereof will be entitled to the benefits of the Registration
Agreement to be dated October 7, 1996, between the Company and the Purchasers
(the "Registration Agreement").

          1.   Representations and Warranties.  The Company represents and
               ------------------------------                             
warrants to, and agrees with, each Purchaser as set forth below in this Section
1.

          (a)  Each of the Preliminary Memorandum and the Final Memorandum as of
     its respective date did not, and the Final Memorandum (as the same may have
     been amended or supplemented) as of the Closing Date will not, contain any
     untrue statement of a material fact or omit to state any material fact
     necessary to make the statements therein, in the light of the circumstances
     under which they were made, not misleading; provided, however, that the
                                                 --------  -------          
     Company makes no representations or warranties as to the information
     contained in or omitted from the Preliminary Memorandum or the Final
     Memorandum in reliance upon and in conformity with information furnished in
     writing to the Company by or on behalf of the Purchasers specifically for
     inclusion in the Preliminary Memorandum or the Final Memorandum (or any
     amendment or supplement thereof or thereto).  All documents incorporated by
     reference in the Preliminary Memorandum or the Final Memorandum that were
     filed under the Exchange Act on or before the Execution Time complied, and
     all such documents that are filed under the Exchange Act after the
     Execution Time and on or before the Closing Date will

                                       2

 
     comply, in all material respects with the applicable requirements of the
     Exchange Act and the rules thereunder.

          (b)  The Company has not taken and will not take, directly or
     indirectly, any action prohibited by Rule 10b-6 under the Exchange Act in
     connection with the offering of the Securities.

          (c)  Neither the Company nor any affiliate (as defined in Rule 501(b)
     of Regulation D under the Act ("Regulation D")) of the Company has
     directly, or through any agent, (i) sold, offered for sale, solicited
     offers to buy or otherwise negotiated in respect of, any security (as
     defined in the Act) that is currently or will be integrated with the sale
     of the Securities in a manner that would require the registration of the
     Securities or the Common Stock issuable upon conversion thereof under the
     Act or (ii) engaged in any form of general solicitation or general
     advertising (within the meaning of Regulation D) in connection with the
     offering of the Securities.

          (d)  Assuming compliance by the Purchasers with their representations,
     warranties and agreements set forth in Section 4 hereof and provided that
     the Securities are otherwise offered and sold by the Purchasers in the
     manner contemplated by this Agreement and the Final Memorandum, except as
     contemplated by the Registration Agreement, it is not necessary in
     connection with the offer, sale and delivery of the Securities in the
     manner contemplated by this Agreement and the Final Memorandum to register
     the Securities under the Act or to qualify the Indenture under the Trust
     Indenture Act of 1939, as amended (the "Trust Indenture Act").

          (e)  None of the Company, its affiliates or any person acting on
     behalf of the Company or its affiliates has engaged in any directed selling
     efforts (as that term is defined in Regulation S under the Act ("Regulation
     S")) with respect to the Securities, and the Company and its affiliates and
     any person acting on its or their behalf have complied with the offering
     restrictions requirement of Regulation S with respect to the offering of
     the Securities.

          (f)  The Company is subject to the reporting requirements of Section
     13 or Section 15(d) of the Exchange Act.

          (g)  The Securities satisfy the eligibility requirements set forth in
     Rule 144A(d)(3) under the Act.

          (h)  The Company has agreed to permit the Securities to be designated
     PORTAL eligible securities, will pay the requisite fees related thereto and
     has provided all necessary information to the National Association of

                                       3

 
     Securities Dealers, Inc. in order to ensure that the Securities are
     designated PORTAL eligible securities.

          (i)  The Company is not an "investment company" within the meaning of
     the Investment Company Act of 1940, as amended (the "Investment Company
     Act"), without taking account of any exemption arising out of the number of
     holders of the Company's securities.

          (j)  The Company has not paid or agreed to pay to any person any
     compensation for soliciting another to purchase any securities of the
     Company (except as contemplated by this Agreement).

          (k)  The information provided by the Company pursuant to Section 5(h)
     hereof will not, at the date thereof, contain any untrue statement of a
     material fact or omit to state any material fact necessary to make the
     statements therein, in the light of the circumstances under which they were
     made, not misleading.

          (l)  The Company has been duly incorporated and is validly existing as
     a corporation in good standing under the laws of the State of California,
     with full corporate power and authority to own its properties and conduct
     its business as described in the Final Memorandum, and is duly qualified to
     do business as a foreign corporation and is in good standing under the laws
     of each jurisdiction which requires such qualification wherein it owns or
     leases properties or conducts business, and in which the failure to be so
     qualified would, in the aggregate in all such cases, have a material
     adverse effect on the business, condition (financial or otherwise), results
     of operation, operations or prospects of the Company and its subsidiaries
     on a consolidated basis (a "Material Adverse Effect").

          (m)  The Company's authorized equity capitalization is as set forth in
     the Final Memorandum; the capital stock of the Company conforms to the
     description thereof contained in the Final Memorandum; the outstanding
     shares of Common Stock have been duly authorized and validly issued and are
     fully paid and nonassessable; the Securities being sold hereunder have been
     duly and validly authorized and, when validly authenticated, issued and
     delivered in accordance with the Indenture and paid for by the Purchasers
     pursuant to this Agreement, will be validly issued and outstanding
     obligations enforceable in accordance with their terms and entitled to the
     benefits of the Indenture.  Upon delivery of the Securities pursuant to
     this Agreement and payment therefor as contemplated herein, the Purchasers
     will acquire good and marketable title to the Securities, free and clear of
     any liens, claims, encumbrances, and security interests ("Liens"),
     restriction on transfer (other than those imposed by state or Federal
     securities laws) or other defect in title.  The appropriate number of
     shares of Common Stock

                                       4

 
     issuable upon conversion of the Securities has been duly reserved for
     issuance, and such shares have been duly and validly authorized, and will
     when issued upon conversion of the Securities against delivery thereof, be
     validly issued, fully paid and non-assessable.  The holders of outstanding
     shares of capital stock of the Company are not entitled to any preemptive
     right or other similar rights to subscribe for the Securities or the shares
     of Common Stock issuable upon conversion thereof.

          (n)  Except as described in the Final Memorandum, there are no
     outstanding options, warrants or other rights calling for the issuance of,
     and no commitments, plans or arrangements to issue, any shares of capital
     stock of the Company or any security convertible into or exchangeable or
     exercisable for capital stock of the Company; except as described in the
     Final Memorandum, there is no holder of any securities of the Company or
     any other person who has the right, contractual or otherwise, to cause the
     Company to sell or otherwise issue to them, or to permit them to underwrite
     the sale of, any of the Securities or the right to have any Common Stock or
     other securities of the Company included in the offering.

          (o)  There is no pending or threatened action, suit or proceeding
     before any court or governmental agency, authority or body or any
     arbitrator involving the Company or any of its subsidiaries of a character
     which would have a Material Adverse Effect which is not adequately
     disclosed in the Final Memorandum.  The descriptions in the Final
     Memorandum of statutes, regulations, contracts, franchises, other
     documents, and pending or threatened actions, suits or proceedings before
     any court or arbitrator, or brought by any governmental agency, authority
     or body are accurate in all material respects and fairly summarize the
     matters therein described.

          (p)  The consolidated financial statements of the Company and its
     consolidated subsidiaries, together with related schedules and notes,
     included in the Final Memorandum present fairly the consolidated financial
     position and the consolidated results of operations and cash flows of the
     Company and its consolidated subsidiaries for the periods or at the dates
     therein specified; the combined financial statements of Electrotech,
     together with related schedules and notes, present fairly the combined
     profit and loss accounts, combined statements of total recognized gains and
     losses and combined balance sheets of Electrotech for the periods or at the
     dates therein specified; such consolidated and combined financial
     statements and related schedules and notes have been prepared in conformity
     with generally accepted accounting principles, consistently applied
     throughout the periods involved except as otherwise noted in such financial
     statements; and the other financial data concerning the Company and its
     subsidiaries and

                                       5

 
     Electrotech set forth in the Final Memorandum (and any amendment or
     supplement thereto) are accurately presented and were derived from such
     financial statements and the books and records of the Company or
     Electrotech, as the case may be.  The pro forma consolidated financial
     statements and other pro forma financial information included or
     incorporated in the Final Memorandum present fairly the information shown
     therein, have been prepared in accordance with the Commission's rules and
     guidelines with respect to pro forma financial statements, have been
     properly compiled on the pro forma bases described therein, and the
     assumptions used in the preparation thereof are reasonable and the
     adjustments used therein are appropriate to give effect to the transactions
     or circumstances referred to therein.  Ernst & Young LLP are independent
     public accountants under the Act and the Exchange Act and the related
     published rules and regulations thereunder.

          (q)  Neither the Company nor any of its subsidiaries is in violation
     of its articles of incorporation or bylaws, or other organizational
     documents, or in violation in any material respect of any law, ordinance,
     administrative or governmental rule or regulation applicable to the Company
     or its subsidiaries, or in violation of any decree of any court or
     governmental agency or body having jurisdiction over the Company or its
     subsidiaries, or in default in any material respect in the performance of
     any obligation, agreement or condition contained in any bond, debenture,
     note or any other evidence of indebtedness or in any material agreement,
     indenture, lease or other instrument to which the Company or its
     subsidiaries are a party or by which it or any of their properties may be
     bound.

          (r)  The Company and each of its subsidiaries has such permits,
     licenses, franchises and authorizations of governmental or regulatory
     authorities ("permits") as are necessary to own their properties and to
     conduct their business in the manner described in the Final Memorandum,
     except where the failure so to have would not, in all such cases in the
     aggregate, result in a Material Adverse Effect; the Company and each
     subsidiary has fulfilled and performed all of their material obligations
     with respect to such permits and no event has occurred which allows, or
     after notice or lapse of time would allow, revocation or termination
     thereof or results in any other material impairment of the rights of the
     holder of any such permit; and none of such permits contains any
     restriction that is materially burdensome to the Company or its
     subsidiaries in conducting its or their business as described in the Final
     Memorandum.

          (s)  Subsequent to the respective dates of which information is given
     in the Final Memorandum, there has not been (1) any material adverse change
     in the condition (financial or otherwise), earnings, operations, business
     or

                                       6

 
     business prospects of the Company, (2) any transaction that is material to
     the Company, except transactions entered into in the ordinary course of
     business, (3) any obligation, direct or contingent, that is material to the
     Company incurred by the Company, except obligations incurred in the
     ordinary course of business, (4) any change in the capital stock or
     outstanding indebtedness of the Company that is material to the Company,
     (5) any dividend or distribution of any kind declared, paid or made on the
     capital stock of the Company or (6) any loss or damage (whether or not
     insured) to the property of the Company which has been sustained or will
     have been sustained which has a Material Adverse Effect.

          (t)  Except as set forth in the Final Memorandum, (1) the Company has
     good and marketable title to all properties and assets described in the
     Final Memorandum as owned by it, free and clear of any pledge, lien,
     security interest, encumbrance, claim or equitable interest, other than
     such as would not have a Material Adverse Effect, (2) the agreements to
     which the Company is a party described in the Final Memorandum are valid
     agreements, enforceable by the Company and its subsidiaries (as
     applicable), except as the enforcement thereof may be limited by applicable
     bankruptcy, insolvency, reorganization, moratorium or other similar laws
     relating to or affecting creditors' rights generally or by general
     equitable principles or with respect to which any unenforceability would
     not have a Material Adverse Effect and, to the Company's knowledge, the
     other contracting party or parties thereto are not in material breach or
     material default under any of such agreements, and (3) the Company has
     valid and enforceable leases for all properties described in the Final
     Memorandum as leased by it, except as the enforcement thereof may be
     limited by applicable bankruptcy, insolvency, reorganization, moratorium or
     other similar laws relating to or affecting creditors' rights generally or
     by general equitable principles or with respect to which any
     unenforceability would not have a Material Adverse Effect.  Except as set
     forth in the Final Memorandum, the Company owns or leases all such
     properties as are necessary to its operations as now conducted or as
     proposed to be conducted.

          (u)  The Company and its subsidiaries have filed all material federal,
     state, local, and foreign tax returns required to be filed, which returns
     are true and correct in all material respects, and the Company and its
     subsidiaries are not in default in the payment of any taxes which were
     payable pursuant to said returns or any assessments with respect thereto,
     except where either (i) the amount of such unpaid taxes is not in excess of
     the amount reserved therefor, or (ii) the Company is contesting such
     default in good faith through appropriate proceedings.

                                       7

 
          (v)  The Company maintains a system of internal accounting controls
     sufficient to provide reasonable assurance that: (i) transactions are
     executed in accordance with management's general or specific
     authorizations; (ii) transactions are recorded as necessary to permit
     preparation of financial statements in conformity with generally accepted
     accounting principles and to maintain accountability for assets; (iii)
     access to assets is permitted only in accordance with management's general
     or specific authorizations; and (iv) the recorded accountability for assets
     is compared with the existing assets at reasonable intervals and
     appropriate action is taken with respect to any differences.

          (w)  The Company and its subsidiaries own or possess adequate licenses
     or other rights to use all patents, trademarks, trademark registrations,
     service marks, service mark registrations, trade names, copyrights,
     licenses, inventions, trade secrets, and know-how or other similar rights
     ("Intellectual Property") described in the Final Memorandum as being owned
     or possessed by them, or necessary for the conduct of its business as
     described in the Final Memorandum; the Company has not infringed, is not
     now infringing, and its business as presently conducted and as proposed to
     be conducted will not cause it to infringe, any Intellectual Property
     belonging to any other person, which infringement or infringements, either
     individually or in the aggregate, could reasonably be expected to have a
     Material Adverse Effect; the Company has not received any claim or notice
     of infringement or potential infringement of any Intellectual Property of
     any other person which could reasonably be expected to have a Material
     Adverse Effect; and neither the Company nor any of its subsidiaries has any
     claim against a third party with respect to the infringement by such third
     party of Intellectual Property of the Company or any such subsidiary
     material to the business or prospects of the Company and its subsidiaries
     considered as a whole.  To the Company's knowledge, the Company is not
     using any confidential information or trade secrets of any former employer
     of any past or present employees.

          (x)  Neither the Company nor any of its subsidiaries is involved in
     any labor dispute with any union or group of employees nor, to the
     knowledge of the Company, is any dispute threatened; and the Company is not
     aware of any existing or imminent labor disturbance by the employees of any
     of its principal suppliers, manufacturers, distributors, licensees or
     contractors which might reasonably be expected to result in a Material
     Adverse Effect or any material adverse change in the condition, financial
     or otherwise, or in the earnings, business affairs or business prospects of
     the Company.
     
          (y)  The Company and its subsidiaries maintain insurance of the types
     and in the amounts generally deemed

                                       8

 
     adequate for their respective businesses, including, but not limited to,
     general liability insurance and insurance covering real and personal
     property owned or leased by the Company or any of its subsidiaries against
     theft, damage, destruction, acts of vandalism and all other risks
     customarily insured against, all of which insurance is in full force and
     effect.

          (z)  This Agreement, the Indenture and the Registration Rights
     Agreement have been duly authorized, executed and delivered by the Company
     and are valid and binding agreements enforceable against the Company in
     accordance with their terms, except to the extent that rights to indemnity
     and contribution hereunder may be limited by federal securities law or the
     public policy of a state with respect to such matters.

          (aa) Neither the issuance and sale of the Securities, the execution,
     delivery or performance of this Agreement by the Company nor the
     consummation by the Company of the transactions contemplated hereby, except
     as contemplated by the Registration Agreement, (i) requires any consent,
     approval, authorization or other order of or registration or filing with
     any court, regulatory body, administrative agency or other governmental
     body, agency or official (assuming compliance by the Purchasers with their
     representations, warranties and agreements set forth in Section 4 hereof
     and provided that the Securities are otherwise offered and sold by the
     Purchasers in the manner contemplated by this Agreement and the Final
     Memorandum) (except such as may have been obtained or such as may be
     required for compliance with the securities or Blue Sky laws of various
     jurisdictions) or conflicts or will conflict with or constitutes or will
     constitute a breach of, or a default under, the articles of incorporation
     or bylaws of the Company or (ii) conflicts or will conflict with or
     constitutes or will constitute a breach of, or a default under, any
     agreement, indenture, lease or other instrument to which the Company is a
     party or by which it or any of its properties may be bound, or violates or
     will violate any statute, law, regulation or filing or judgment,
     injunction, order or decree applicable to the Company or any of its
     properties, or will result in the creation or imposition of any lien,
     charge or encumbrance upon any property or assets of the Company pursuant
     to the terms of any agreement or instrument to which it is a party or by
     which it may be bound or to which any of its property or assets is subject.

          (ab) The representations and warranties of the Company contained in
     the Share Purchase Agreement are true and correct in all material respects
     at and as of the date hereof as if made at and as of such date.  The
     Company has no reason to believe that such representations and warranties
     will not be true and correct as of the consummation of the Acquisition
     ("Acquisition Closing

                                       9

 
     Date"), that the representations and warranties of Electrotech contained in
     the Share Purchase Agreement are or will be untrue or inaccurate as of the
     date hereof and the Acquisition Closing Date, or that any of the conditions
     to the obligations of Electrotech or the Company to consummate the
     Acquisition will not be satisfied (without waiver) prior to the Acquisition
     Closing Date.

          2.   Purchase and Sale.
               ----------------- 

          (a)  Subject to the terms and conditions and in reliance upon the
     representations and warranties herein set forth, the Company agrees to sell
     to the Purchasers, and the Purchasers agree to purchase from the Company,
     the Firm Securities at a purchase price of 96.25% of the principal amount
     thereof, plus accrued interest, if any, from October 7, 1996, to the
     Closing Date (the difference between such amount and 100% of the principal
     amount of the Firm Securities shall be referred to as the "Firm Discount");
     provided, however, that the Company shall pay, or cause the Trustee to pay,
     to the Purchasers the amount of the Discount, together with interest earned
     thereon, only upon the release of the Collateral under Section 4.8(c)(i) of
     the Indenture.  Each such Security will be convertible at the option of the
     holder into shares of Common Stock of the Company at a conversion price
     $15.635 per share of Common Stock, subject to adjustment as specified in
     the Final Memorandum.

          (b)  Subject to the terms and conditions and in reliance upon the
     representations and warranties herein set forth, the Company hereby grants
     an option (the "Option") to the Purchasers to purchase the Option
     Securities at a purchase price of 96.25% of the principal amount thereof,
     plus accrued interest, if any, from October 7, 1996, to the settlement date
     for the Option Securities (the difference between such amount and 100% of
     the principal amount of the Option Securities purchased shall be referred
     to as the "Option Discount"); provided, however, that the Company will pay,
     or cause the Trustee to pay, to the Purchasers the amount of the Option
     Discount, together with interest earned thereon, only upon the release of
     the Collateral under Section 4.8(c)(i) of the Indenture.  The Option may be
     exercised only to cover over-allotments in the sale of the Firm Securities
     by the Purchasers.  The Option may be exercised in whole or in part at any
     time (but not more than once) on or before the 30th day after the date of
     the Final Memorandum upon written or telegraphic notice by the Purchasers
     to the Company setting forth the principal amount of Option Securities as
     to which the Purchasers are exercising the Option and the settlement date
     therefor.  Delivery of certificates for the Option Securities, and payment
     therefor, shall be made as provided in Section 3 hereof.

                                       10

 
          (c)  The Purchasers shall notify the Company of the completion of the
     sale of the Securities by the Purchasers.

          3.   Delivery and Payment.  Delivery of and payment for the Firm
               --------------------                                       
Securities and Option Securities (if the option provided for in Section 2(b)
hereof shall have been exercised on or before the third business day prior to
the Closing Date) shall be made at 10:00 AM, New York City time, on October 7,
1996, or such later date as the Purchasers and the Company shall agree (such
date and time of delivery and payment for the Securities being herein called the
"Closing Date").  Delivery of the Securities shall be made to the Purchasers
against payment by the Purchasers of 100% of the principal amount of the Firm
Securities to or upon the order of the Company by certified or official bank
check or checks drawn on or by a New York Clearing House bank and payable in
next day funds.  Delivery of the Securities shall be made at such location as
the Purchasers shall reasonably designate at least one (1) business day in
advance of the Closing Date and payment for the Securities shall be made at the
office of Munger, Tolles & Olson, 355 South Grand Avenue, Los Angeles,
California.  Certificates for the Securities shall be registered in such names
and in such denominations as the Purchasers may request not less than three full
business days in advance of the Closing Date.

          The Company agrees to have the Securities available for inspection,
checking and packaging by the Purchasers in New York, New York, not later than
1:00 PM on the business day prior to the Closing Date.

          If the Option is exercised after the third business day prior to the
Closing Date, the Company will deliver (at the expense of the Company) to the
Purchasers, at Seven World Trade Center, New York, New York, on the date
specified by the Purchasers (which shall be within three business days after
exercise of the Option), certificates for the Option Securities in such names
and denominations as the Purchasers shall have requested against payment of 100%
of the principal amount of the purchased Option Securities to or upon order of
the Company by certified or official bank check or checks drawn on or by a New
York Clearing House bank and payable in next day funds.  If settlement for the
Option Securities occurs after the Closing Date, the Company will deliver to the
Purchasers on the settlement date for the Option Securities, and the obligation
of the Purchasers to purchase the Option Securities shall be conditioned upon
receipt of, supplemental opinions, certificates and letters confirming as of
such date the opinions, certificates and letters delivered on the Closing Date
pursuant to Section 6 hereof.

          4.   Offering of Securities; Restrictions on Transfer.
               ------------------------------------------------ 

          (a)  Each of the Purchasers, severally and not jointly, represents and
     warrants to and agrees with the Company that (i) it has not solicited and
     will not solicit any offer to buy, and has not offered and will not offer
     to sell, the

                                       11

 
     Securities by means of any form of general solicitation or general
     advertising (within the meaning of Regulation D) or in any manner involving
     a public offering within the meaning of Section 4(2) of the Act or, with
     respect to Securities sold in reliance on Regulation S, by means of any
     directed selling efforts and (ii) it has solicited and will solicit offers
     to buy the Securities only from, and has offered and will offer, sell or
     deliver the Securities only to, (A) persons who it reasonably believes to
     be qualified institutional buyers (as defined in Rule 144A under the Act)
     or, if any such person is buying for one or more institutional accounts for
     which such person is acting as fiduciary or agent, only when such person
     has represented to it that each such account is a qualified institutional
     buyer, to whom notice has been given that such sale or delivery is being
     made in reliance on Rule 144A, and, in each case, in transactions under
     Rule 144A, (B) persons who it reasonably believes to be institutional
     "accredited investors" (as defined in Rule 501(a)(1), (2), (3) or (7) of
     Regulation D), and who provide to it a letter in the form of Exhibit A
     hereto or (C) persons to whom, and under circumstances which, it reasonably
     believes offers and sales of Securities may be made without registration of
     the Securities under the Act in reliance upon Regulation S thereunder.
     Each of the Purchasers also represents and warrants and agrees that it has
     offered and will offer to sell the Securities only to, and has solicited
     and will solicit offers to buy the Securities only from, persons that in
     purchasing such Securities will be deemed to have represented and agreed as
     provided under "Investor Representations and Restrictions on Resale" in
     Exhibit B hereto.

          (b)  Each of the Purchasers represents and warrants to and agrees with
     the Company that (i) it has not offered or sold, and will not offer or sell
     any Securities to persons in the United Kingdom, except to persons whose
     ordinary activities involve them in acquiring, holding, managing or
     disposing of investments (as principal or as agent) for the purposes of
     their businesses or otherwise in circumstances which have not resulted and
     will not result in an offer to the public in the United Kingdom, within the
     meaning of the Public Offers of Securities Regulations 1995 (the
     "Regulations"), (ii) it has complied and will comply with all applicable
     provisions of the Financial Services Act 1986 and the Regulations with
     respect to anything done by it in relation to the Securities in, from or
     otherwise involving the United Kingdom, and (iii) it has only issued or
     passed on and will only issue or pass on to any person in the United
     Kingdom any document received by it in connection with the issue of the
     Securities if that person is of a kind described in Article 11(3) of the
     Financial Services Act 1986 (Investment Advertisements) (Exemptions) Order
     1996 or is a person to whom such document may otherwise lawfully be issued
     or passed on.

                                       12

 
          5.   Agreements.  The Company agrees with the Purchasers that:
               ----------                                               

          (a)  The Company will furnish to the Purchasers, without charge,
     during the period mentioned in paragraph (d) below, as many copies of the
     Final Memorandum and any supplements and amendments thereof or thereto as
     the Purchasers may reasonably request. The Company will pay the expenses of
     printing or other production of all documents relating to the offering.

          (b)  The Company will not amend or supplement the Final Memorandum,
     other than by filing documents under the Exchange Act that are incorporated
     by reference therein, without the prior consent of the Purchasers.  Prior
     to the completion of the sale of the Securities by the Purchasers, the
     Company will not file any document under the Exchange Act that is
     incorporated by reference in the Final Memorandum unless the Company has
     furnished you a copy for your review prior to filing and will not file any
     such document to which you reasonably and timely object.

          (c)  The Company will promptly advise the Purchasers when, prior to
     the completion of the sale of the Securities by the Purchasers, any
     document filed under the Exchange Act which is incorporated by reference in
     the Final Memorandum shall have been filed with the Securities and Exchange
     Commission (the "Commission").

          (d)  If at any time prior to the completion of the sale of the
     Securities by the Purchasers, any event occurs as a result of which the
     Final Memorandum as then amended or supplemented would include any untrue
     statement of a material fact or omit to state any material fact necessary
     to make the statements therein in the light of the circumstances under
     which they were made not misleading, or if it shall be necessary to amend
     or supplement the Final Memorandum (including any document incorporated by
     reference therein which was filed under the Exchange Act) to comply with
     the Exchange Act or the rules thereunder or other applicable law, the
     Company promptly will notify the Purchasers of the same and, subject to
     paragraph (b) of this Section 5, will prepare and provide to the Purchasers
     pursuant to paragraph (a) of this Section 5 an amendment or supplement
     which will correct such statement or omission or effect such compliance
     and, in the case of such an amendment or supplement which is to be filed
     under the Exchange Act and which is incorporated by reference in the Final
     Memorandum, will file such amendment or supplement with the Commission.

          (e)  The Company will cooperate with you and your counsel in
     endeavoring to obtain the qualification of the Securities for sale under
     the laws of such jurisdictions as the Purchasers may reasonably designate,
     and will maintain

                                       13

 
     such qualifications in effect so long as reasonably required for the sale
     of the Securities; provided, however, that the Company shall not be
                        --------  -------                               
     required to file any general consent to service of process or to qualify as
     a foreign corporation or as a dealer in securities in any jurisdiction in
     which it is not so qualified or to subject itself to taxation in respect of
     doing business in any jurisdiction in which it is not otherwise so subject.
     The Company will promptly advise the Purchasers of the receipt by the
     Company of any notification with respect to (i) the suspension of the
     qualification of the Securities for sale in any jurisdiction or (ii) the
     initiation or threatening of any proceeding for such purpose.

          (f)  Neither the Company nor any affiliate (as defined in Rule 501(b)
     of Regulation D) of the Company will solicit any offer to buy or offer or
     sell the Securities by means of any form of general solicitation or general
     advertising (within the meaning of Regulation D).

          (g)  None of the Company, its affiliates nor any person (excluding the
     Purchasers) acting on behalf of the Company or its affiliates will engage
     in any directed selling efforts with respect to the Securities within the
     meaning of Regulation S, and the Company, its affiliates and each such
     person acting on its or their behalf will comply with the offering
     restrictions requirement of Regulation S.

          (h)  The Company shall, during any period in the three years after the
     Closing Date in which the Company is not subject to Section 13 or 15(d) of
     the Exchange Act, make available, upon request, to any holder of the
     Securities or Common Stock issued upon conversion thereof in connection
     with any sale thereof and any prospective purchaser of Securities or Common
     Stock issued upon conversion thereof from such holder the information
     specified in Rule 144A(d)(4) under the Act.

          (i)  The Company will not, and will not permit any of its affiliates
     (as defined in Rule 501(b) of Regulation D) to, sell any Securities or
     Common Stock issued upon conversion thereof which constitute "restricted
     securities" under Rule 144 that have been reacquired by any of them.

          (j)  Neither the Company nor any affiliate (as defined in Rule 501(b)
     of Regulation D) will sell, offer for sale or solicit offers to buy or
     otherwise negotiate in respect of any security (as defined in the Act) the
     offering of which security will be integrated with the sale of the
     Securities in a manner that would require the registration of the issuance
     and sale by the Company of the Securities or Common Stock issuable upon
     conversion thereof under the Act.

                                       14

 
          (k)  The Company shall include information substantially in the form
     set forth in Exhibit B in each Final Memorandum.

          (l)  The Company shall use its best efforts in cooperation with the
     Purchasers to permit the Securities to be eligible for clearance and
     settlement through the Depository Trust Company.

          (m)  The Company will not, for a period of 90 days following the
     Execution Time without prior written consent of the Purchasers (which
     consent shall not be unreasonably withheld), offer, sell or contract to
     sell, or otherwise dispose of, directly or indirectly, or announce the
     offering of, any debt securities issued or guaranteed by the Company, any
     preferred stock or Common Stock of the Company or any security convertible
     into or exchangeable for preferred stock or Common Stock (other than the
     Securities); provided, however, that the Company may (1) issue Common Stock
                  --------  -------                                             
     upon exercise of presently outstanding options and warrants, (2) grant
     options pursuant to its 1991 Stock Option Plan, and (3) issue options and
     shares of its Common Stock to the shareholders of Electrotech as provided
     in the Share Purchase Agreement.

          (n)  The Company will apply the net proceeds from the sale of the
     Securities substantially in accordance with the description set forth in
     the Final Memorandum under the heading "Use of Proceeds."

          6.   Conditions to the Obligations of the Purchasers.  The obligations
               -----------------------------------------------                  
of the Purchasers to purchase the Firm Securities and the Option Securities, as
the case may be, shall be subject to the accuracy of the representations and
warranties on the part of the Company contained herein as of the Execution Time
and the Closing Date, to the accuracy of the statements of the Company made in
any certificates pursuant to the provisions hereof, to the performance by the
Company of its obligations hereunder and to the following additional conditions:

          (a)  The Company shall have furnished to the Purchasers the opinion of
     Riordan & McKinzie, counsel for the Company, dated the Closing Date, to the
     effect that:

               (i)    the Company has been duly incorporated and is validly
          existing as a corporation in good standing under the laws of the
          jurisdiction in which it is chartered or organized, with full
          corporate power and authority to own and lease its properties and
          conduct its business as described in the Final Memorandum and is duly
          qualified to do business as a foreign corporation and is in good
          standing under the laws of each jurisdiction which requires such
          qualification wherein it owns or leases material properties or
          conducts material business, and in which the failure to

                                       15

 
          be so qualified or to be in good standing would, in the aggregate in
          all such cases, have a Material Adverse Effect;

               (ii)   the Company's authorized equity capitalization is as set
          forth in the Final Memorandum; the Securities and the Common Stock
          conform to the description thereof contained in the Final Memorandum
          in all material respects; the holders of the outstanding shares of
          capital stock of the Company are not entitled to any preemptive or, to
          such counsel's knowledge, any other similar rights to subscribe for
          the Securities or the shares of Common Stock issuable upon conversion
          thereof; and the shares of Common Stock initially issuable upon
          conversion of the Securities have been duly and validly authorized and
          reserved for issuance upon such conversion and, when issued upon such
          conversion, will be validly issued, fully paid and nonassessable;

               (iii)  to the best knowledge of such counsel, except as described
          in the Final Memorandum, there are no outstanding rights, warrants, or
          options to acquire, or instruments convertible into or exchangeable
          for, any shares of capital stock or equity interest in the Company or
          its subsidiaries;

               (iv)   to the best knowledge of such counsel, there is no pending
          or threatened action, suit or proceeding before any court or
          governmental agency, authority or body or any arbitrator involving the
          Company or any of its subsidiaries that would have a Material Adverse
          Effect on the Company that is not adequately disclosed in the Final
          Memorandum, and there is no material franchise, contract or other
          material document which would be required to be disclosed in a
          Registration Statement on Form S-1 filed under the Act and which is
          not described in the Final Memorandum; the descriptions in the Final
          Memorandum of statutes, regulations, contracts, franchises or other
          documents, pending or threatened actions, suits or proceedings before
          any court or arbitrator, or brought by any governmental agency,
          authority or body fairly present the information shown;

               (v)    the Indenture has been duly authorized, executed and
          delivered by the Company, and, assuming due authorization, execution
          and delivery by the Trustee, constitutes a legal, valid and binding
          instrument enforceable against the Company in accordance with its
          terms (subject, as to enforcement of remedies, to applicable
          bankruptcy, reorganization, insolvency, moratorium or other laws
          affecting creditors' rights generally from time to time in effect and
          general principles of equity, whether enforcement

                                       16

 
          is considered in a proceeding in equity or at law and the discretion
          of the court before which any proceeding therefor may be brought); and
          the Securities have been duly authorized by the Company and, when
          executed and authenticated in accordance with the provisions of the
          Indenture and delivered to and paid for by the Purchasers pursuant to
          this Agreement, will constitute legal, valid and binding obligations
          of the Company entitled to the benefits of the Indenture; and the
          statements set forth under the "Description of the Notes" in the Final
          Memorandum, insofar as such statements purport to summarize certain
          provisions of the Securities and the Indenture, provide a fair summary
          of such provisions;

               (vi)   the Company has the corporate power and authority to enter
          into this Agreement, the Registration Agreement and the Share Purchase
          Agreement; this Agreement, the Registration Agreement and the Share
          Purchase Agreement have been duly authorized, executed and delivered
          by the Company;

               (vii)  provided that the Securities are offered and sold in the
          manner contemplated by the Purchase Agreement and the Final
          Memorandum, and assuming compliance by the Company and the Purchasers
          with their respective representations, warranties and agreements with
          respect thereto as set forth in the Purchase Agreement and the
          compliance by the Shareholder parties thereto with their
          representations, warranties and covenants set forth in the Share
          Purchase Agreement, no consent, approval, authorization or order of
          any court or governmental agency or body is required for the
          performance by the Company of its obligations hereunder or under the
          Share Purchase Agreement, except (i) such as may be required under the
          blue sky laws of any jurisdiction in connection with the purchase and
          distribution of the Securities by the Purchasers (as to which such
          counsel need express no opinion), (ii) as contemplated by the
          Registration Agreement and the separate Registration Agreement
          attached as Exhibit D to the Share Purchase Agreement and (iii) such
          other approvals (specified in such opinion) as have been obtained;

               (viii) provided that the Securities are offered and sold in the
          manner contemplated by the Purchase Agreement and the Final
          Memorandum, and assuming compliance by the Company and the Purchasers
          with their respective representations, warranties and agreements with
          respect thereto as set forth in the Purchase Agreement and the
          compliance by the Shareholder parties thereto with their
          representations, warranties and covenants set forth in the Share
          Purchase Agreement, neither the issue and sale of the Securities, the

                                       17

 
          execution and delivery of the Indenture, the performance by the
          Company of its obligations under this Agreement, the Share Purchase
          Agreement, the Indenture, the Registration Agreement or the Notes, nor
          the fulfillment of the terms hereof will conflict with, result in a
          breach or violation of, or constitute a default under any law (except
          Blue Sky laws, as to which such counsel expresses no opinion) or the
          articles of incorporation or by-laws of the Company or the terms of
          any indenture or other agreement or instrument known to such counsel
          to which the Company or any of its subsidiaries is a party or by which
          it is bound or any judgment, order or decree known to such counsel to
          be applicable to the Company or any of its subsidiaries of any court,
          regulatory body, administrative agency, governmental body or
          arbitrator having jurisdiction over the Company or any of its
          subsidiaries; provided, however, that such counsel need express no
          opinion as to whether any such conflict, breach, violation or default
          will result under any covenant, restriction or provision with respect
          to financial ratios or tests or any aspect of the financial condition
          or results of operations of the Company;

               (ix)   provided that the Securities are offered and sold in the
          manner contemplated by the Purchase Agreement and the Final
          Memorandum, and assuming compliance by the Company and the Purchasers
          with their respective representations, warranties and agreements with
          respect thereto as set forth in the Purchase Agreement, it is not
          necessary in connection with the offer, sale and delivery by the
          Company of the Securities in the manner contemplated by this Agreement
          to register the Securities under the Act or to qualify the Indenture
          under the Trust Indenture Act; and

          In addition, such counsel shall state that, in the course of
     preparation by the Company of the Final Memorandum, such counsel has
     participated in conferences with officers and other representatives of the
     Company, representatives of the independent public accountants for the
     Company, representatives of the Purchasers and representatives of counsel
     for the Purchasers, at which conferences such counsel made inquiries of
     such officers, representatives and accountants and discussed the contents
     of the Final Memorandum and related matters and (without taking any further
     action to verify independently the statements made in the Final Memorandum
     and, except solely as expressly stated in the foregoing opinion, without
     assuming responsibility for the accuracy, completeness or fairness of such
     statements) nothing has come to the attention of such counsel which would
     lead such counsel to believe that as of the date thereof or on the Closing
     Date, the Final Memorandum contained or contains an untrue

                                       18

 
     statement of a material fact or omitted or omits to state a material fact
     necessary to make the statements therein, in the light of the circumstances
     under which they were made, not misleading (it being understood that such
     counsel need not express any statement with respect to the financial
     statements, schedules and other financial information included in the Final
     Memorandum).

          In rendering such opinion, such counsel may rely (A) as to matters
     involving the application of laws of any jurisdiction other than the State
     of California or the United States, to the extent they deem proper and
     specified in such opinion, upon the opinion of other counsel of good
     standing whom they believe to be reliable and who are satisfactory to
     counsel for the Purchasers and (B) as to matters of fact, to the extent
     they deem proper, on certificates of responsible officers of the Company
     and public officials.  References to the Final Memorandum in this paragraph
     (a) include any amendments or supplements thereof or thereto at the Closing
     Date.

          (b)  The Purchasers shall have received from Munger, Tolles & Olson,
     counsel for the Purchasers, such opinion or opinions, dated the Closing
     Date, with respect to the issuance and sale of the Securities, the
     Indenture, the Final Memorandum (together with any amendment or supplement
     thereof or thereto) and other related matters as the Purchasers may
     reasonably require, and the Company shall have furnished to such counsel
     such documents as they request for the purpose of enabling them to pass
     upon such matters.

          (c)  The Company shall have furnished to the Purchasers a certificate
     of the Company, signed on behalf of the Company by the Chairman of the
     Board or the President and the principal financial or accounting officer of
     the Company, dated the Closing Date, to the effect that the signers of such
     certificate have carefully examined the Final Memorandum, any amendment or
     supplement to the Final Memorandum and this Agreement and that:

               (i)    the representations and warranties of the Company in this
          Agreement are true and correct in all material respects on and as of
          the Closing Date with the same effect as if made on the Closing Date
          and the Company has complied in all material respects with all the
          agreements and satisfied all the conditions on its part to be
          performed or satisfied pursuant to this agreement at or prior to the
          Closing Date; and

               (ii)   since the date of the most recent financial statements
          incorporated by reference in the Final Memorandum, there has been no
          material adverse change in the condition (financial or other),
          earnings, business or properties of the Company and its

                                       19

 
          subsidiaries taken as a whole, whether or not arising from
          transactions in the ordinary course of business, except as set forth
          in or contemplated in the Final Memorandum.

          (d)  At the Execution Time and at the Closing Date, Ernst & Young LLP
     shall have furnished to the Purchasers a letter or letters, dated
     respectively as of the Execution Time and as of the Closing Date, in form
     and substance satisfactory to the Purchasers, confirming that they are
     independent accountants within the meaning of the Act and the Exchange Act
     and the respective applicable published rules and regulations thereunder
     and stating in effect that:

               (i)    in their opinion the audited financial statements and
          financial statement schedules included or incorporated by reference in
          the Final Memorandum and reported on by them comply in form in all
          material respects with the applicable accounting requirements of the
          Act and the published rules and regulations thereunder;

               (ii)   on the basis of procedures (but not an examination in
          accordance with generally accepted auditing standards) consisting of
          the following:

                      (1)  a reading of the minutes of the meetings of
               stockholders, directors and the Audit and Compensation Committees
               of the Company and Electrotech and, where applicable, their
               subsidiaries;

                      (2)  performing the procedures specified by the American
               Institute of Certified Public Accountants for a review of interim
               financial information as described in SAS No. 71, Interim
               Financial Information, on the unaudited interim financial
               statements of the Company and its consolidated subsidiaries
               included in the Final Memorandum and reading the unaudited
               interim financial data for the period from the date of the latest
               audited balance sheet included in the Final Memorandum to the
               date of the latest available interim financial data; and

                      (3)  inquiries of certain officials of the Company and
               Electrotech who have responsibility for financial and accounting
               matters of the Company and Electrotech regarding their
               subsidiaries as to transactions and events subsequent to the
               December 31, 1995 and June 30, 1996 audited financial statements
               incorporated in the Final Memorandum,

                                       20

 
          nothing came to their attention which caused them to believe that:

                      (1)  the unaudited financial statements included in the
               Final Memorandum do not comply in form in all material respects
               with the applicable accounting requirements of the Act and the
               related published rules and regulations;

                      (2)  any material modifications should be made to the
               unaudited financial statements for them to be in conformity with
               generally accepted accounting principles; or

                      (3)  with respect to the period subsequent to June 30,
               1996, there were any changes, at a specified date not more than
               five business days prior to the date of the letter, in the Long-
               Term Debt or Capital Stock of the Company or Electrotech and
               their consolidated subsidiaries or decreases in the Shareholders'
               Equity of the Company or Electrotech as compared with the amounts
               shown on the June 30, 1995 consolidated balance sheet of the
               Company and combined balance sheet of Electrotech included in the
               Final Proxy Statement, or for the period from July 1, 1996 to
               such specified date there were any decreases, as compared with
               the corresponding period in the preceding year, in Revenue, or in
               total or per share amounts of Net Income (Loss) of the Company
               and Electrotech and their consolidated subsidiaries, except in
               all instances for changes or decreases set forth in such letter,
               in which case the letter shall be accompanied by an explanation
               by the Company or Electrotech as to the significance thereof
               unless said explanation is not deemed necessary by the
               Representatives; and

               (iii)  they are unable to and do not express any opinion on the
          pro forma capitalization or the "Pro Forma Information" included or
          incorporated in the Final Memorandum or on the pro forma adjustments
          applied to the historical amounts included in such statements (the
          "Pro Forma Information"); however, for purposes of such letter they
          have:

                      (1)  read the Pro Forma Information;

                      (2)  made inquiries of certain officials of the Company
               who have responsibility for financial and accounting matters
               about the basis for their determination of the pro forma
               adjustments and whether the Pro Forma Information above complies
               in form in all material respects with the

                                       21

 
               applicable accounting requirements of Rule 11-02 of Regulation S-
               X;

                      (3)  compared the historical amounts in the Pro Forma
               Information with the Company's or Electrotech's audited financial
               statements or accounting records; and

                      (4)  proved the arithmetic accuracy of the application of
               the pro forma adjustments to the historical amounts in the Pro
               Forma Information; and

               on the basis of such procedures, and such other inquiries and
               procedures as may be specified in such letter, nothing came to
               their attention that caused them to believe that the Pro Forma
               Information included in the Final Memorandum does not comply as
               to form in all material respects with the applicable requirements
               of Rule 11-02 of Regulation S-X and that the pro forma
               adjustments have not been properly applied to the historical
               amounts in the compilation of such statements; and

               (iv)   they have performed certain other specified procedures as
          a result of which they determined that certain information of an
          accounting, financial or statistical nature (which is limited to
          accounting, financial or statistical information derived from the
          general accounting records of the Company and Electrotech and their
          subsidiaries) included or incorporated by reference in the Final
          Memorandum, including the information set forth under the captions
          "Summary Financial and Pro Forma Data," "Risk Factors", "Selected
          Consolidated Financial Data of PMT," "Selected Consolidated Financial
          Data of Electrotech," "Management's Discussion and Analysis of
          Financial Condition and Results of Operations of PMT," "Management's
          Discussion and Analysis of Financial Condition and Results of
          Operation of Electrotech," and "Business" therein, the information
          included or incorporated in Items 1, 6, 7, and 11 of the Company's
          Annual Report on Form 10-K, incorporated by reference in the Final
          Memorandum, and the information included in the "Management's
          Discussion and Analysis of Financial Condition and Results of
          Operations" included or incorporated in the Company's Quarterly
          Reports on Form 10-Q incorporated by reference in the Final
          Memorandum, agrees with the accounting records of the Company and its
          subsidiaries, excluding any questions of legal interpretation.

                                       22

 
          References to the Final Memorandum in this paragraph (d) include any
     amendment or supplement thereof or thereto at the date of the letter.

          (e)  Subsequent to the Execution Time or, if earlier, the dates as of
     which information is given in the Final Memorandum (exclusive of any
     amendment or supplement thereof or thereto), there shall not have been (i)
     any change or decrease specified in the letter or letters referred to in
     paragraph (d) of this Section 6 or (ii) any change, or any development
     involving a prospective change, in or affecting the business or properties
     of the Company and its subsidiaries the effect of which, in any case
     referred to in clause (i) or (ii) above, is, in the reasonable judgment of
     the Purchasers, so material and adverse as to make it impractical or
     inadvisable to market the Securities as contemplated by the Final
     Memorandum (exclusive of any amendment or supplement thereof or thereto).

          (f)  Prior to the Closing Date, the Company shall have furnished to
     the Purchasers such further information, certificates and documents as the
     Purchasers may reasonably request.

          (g)  At the Execution Time, the Company shall have furnished to the
     Purchasers a letter substantially in the form of Exhibit C hereto from
     persons listed on Exhibit C addressed to the Purchasers, in which each such
     person agrees not to offer, sell or contract to sell, or otherwise dispose
     of, directly or indirectly, or announce an offering of, any shares of
     preferred stock or Common Stock beneficially owned by such persons or any
     securities convertible into, or exchangeable for, shares of preferred stock
     or Common Stock for a period of 90 days following the closing of the Share
     Purchase Agreement without the prior written consent of Salomon Brothers
     Inc, other than shares of Common Stock disposed of as bona fide gifts.

          If any of the conditions specified in this Section 6 shall not have
been fulfilled in all material respects when and as provided in this Agreement,
or if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in form
and substance to the Purchasers and counsel for the Purchasers, this Agreement
and all obligations of the Purchasers hereunder may be canceled at, or at any
time prior to, the Closing Date by the Purchasers.  Notice of such cancellation
shall be given to the Company in writing or by telephone or telefax confirmed in
writing.

     The documents required to be delivered by this Section 6 shall be delivered
at the office of Munger, Tolles & Olson, counsel for the Purchasers, at 355
South Grand Avenue, Los Angeles, California 90071 on the Closing Date.

                                       23

 
          7.   Reimbursement of Purchasers' Expenses.  If the sale of the
               -------------------------------------                     
Securities provided for herein is not consummated because any condition to the
obligations of the Purchasers set forth in Section 6 hereof (other than the
condition set forth in Section 6(b) (solely to the extent the inability to
deliver such an opinion is due to general industry or economic conditions
affecting the business or properties of the Company and its subsidiaries), or
the condition set forth in Section 6(e)(ii) solely by reason of any change, or
any development involving a prospective change, relating to general industry or
economic conditions) is not satisfied, because of any termination pursuant to
clause (i) of Section 9 hereof or because of any refusal, inability or failure
on the part of the Company to perform any agreement herein or comply with any
provision hereof other than by reason of a default by the Purchasers, the
Company will reimburse the Purchasers upon demand for all reasonable and duly
documented out-of-pocket expenses (including reasonable fees and disbursements
of counsel) that shall have been incurred by it in connection with the proposed
purchase and sale of the Securities.

          8.   Indemnification and Contribution.
               -------------------------------- 

          (a)  The Company agrees to indemnify and hold harmless each Purchaser,
     the directors, officers, employees and agents of each Purchaser and each
     person who controls each Purchaser within the meaning of either the Act or
     the Exchange Act against any and all losses, claims, damages or
     liabilities, joint or several, to which they or any of them may become
     subject under the Act, the Exchange Act or other Federal or state statutory
     law or regulation, at common law or otherwise, insofar as such losses,
     claims, damages or liabilities (or actions in respect thereof) arise out of
     or are based upon any untrue statement or alleged untrue statement of a
     material fact contained in the Preliminary Memorandum, the Final Memorandum
     or any information provided by the Company to any holder or prospective
     purchaser of Securities pursuant to Section 5(h), or in any amendment
     thereof or supplement thereto, or arise out of or are based upon the
     omission or alleged omission to state therein a material fact required to
     be stated therein or necessary to make the statements therein not
     misleading, and agrees to reimburse each such indemnified party, as
     incurred, for any legal or other expenses reasonably incurred by them in
     connection with investigating or defending any such loss, claim, damage,
     liability or action; provided, however, that the Company will not be liable
                          --------  -------                                     
     in any such case to the extent that any such loss, claim, damage or
     liability arises out of or is based upon any such untrue statement or
     alleged untrue statement or omission or alleged omission made in the
     Preliminary Memorandum or the Final Memorandum, or in any amendment thereof
     or supplement thereto, in reliance upon and in conformity with written
     information furnished to the Company by or on behalf of a Purchaser
     specifically for inclusion therein; provided, further, that the
     indemnification contained in this paragraph 8(a) with

                                       24

 
     respect to any Preliminary Memorandum shall not inure to the benefit of any
     Purchaser (or of any person controlling such Purchaser) from whom the
     person asserting any such loss, claim, damage or liability purchased the
     Securities which are the subject thereof, if such person did not receive a
     copy of the Final Memorandum, provided the Company has delivered the Final
     Memorandum to the Purchasers in requisite quantity on a timely basis to
     permit the delivery thereof at or prior to the confirmation of the sale of
     such Securities to such person, and any untrue statement or omission of a
     material fact contained in such Preliminary Memorandum was corrected in the
     Final Memorandum.  This indemnity agreement will be in addition to any
     liability which the Company may otherwise have.

          (b)  Each Purchaser severally agrees to indemnify and hold harmless
     the Company, its directors, its officers, and each person who controls the
     Company within the meaning of either the Act or the Exchange Act, to the
     same extent as the foregoing indemnity from the Company to the Purchasers,
     but only with reference to written information furnished to the Company by
     or on behalf of such Purchaser specifically for inclusion in the
     Preliminary Memorandum or the Final Memorandum, or in any amendment thereof
     or supplement thereto. This indemnity agreement will be in addition to any
     liability which the Purchasers may otherwise have. The Company acknowledges
     that the statements set forth in the last paragraph of the cover page, in
     the last two paragraphs of page 3 and under the heading "Plan of
     Distribution" in the Preliminary Memorandum and the Final Memorandum
     constitute the only information furnished in writing by or on behalf of the
     Purchasers for inclusion in the Preliminary Memorandum or the Final
     Memorandum.

          (c)  Promptly after receipt by an indemnified party under this Section
     8 of notice of the commencement of any action, such indemnified party will,
     if a claim in respect thereof is to be made against the indemnifying party
     under this Section 8, notify the indemnifying party in writing of the
     commencement thereof; but the failure so to notify the indemnifying party
     (i) will not relieve it from liability under paragraph (a) or (b) above
     unless and to the extent it did not otherwise learn of such action and such
     failure results in the forfeiture by the indemnifying party of substantial
     rights and defenses and (ii) will not, in any event, relieve the
     indemnifying party from any obligations to any indemnified party other than
     the indemnification obligation provided in paragraph (a) or (b) above.  The
     indemnifying party shall be entitled to appoint counsel of the indemnifying
     party's choice at the indemnifying party's expense to represent the
     indemnified party in any action for which indemnification is sought (in
     which case the indemnifying party shall not thereafter be responsible for
     the fees and expenses of any separate counsel retained by the indemnified
     party or parties except as set forth below);

                                       25

 
     provided, however, that such counsel shall be reasonably satisfactory to
     --------  -------                                                       
     the indemnified party.  Notwithstanding the indemnifying party's election
     to appoint counsel to represent the indemnified party in an action, the
     indemnified party shall have the right to employ separate counsel
     (including local counsel), and the indemnifying party shall bear the
     reasonable fees, costs and expenses of such separate counsel if (i) the use
     of counsel chosen by the indemnifying party to represent the indemnified
     party would present such counsel with a conflict of interest, (ii) the
     actual or potential defendants in, or targets of, any such action include
     both the indemnified party and the indemnifying party and the indemnified
     party shall have reasonably concluded that there may be legal defenses
     available to it and/or other indemnified parties which are different from
     or additional to those available to the indemnifying party, (iii) the
     indemnifying party shall not have employed counsel reasonably satisfactory
     to the indemnified party to represent the indemnified party within a
     reasonable time after notice of the institution of such action or (iv) the
     indemnifying party shall authorize the indemnified party to employ separate
     counsel at the expense of the indemnifying party.  An indemnifying party
     will not, without the prior written consent of the indemnified parties,
     settle or compromise or consent to the entry of any judgment with respect
     to any pending or threatened claim, action, suit or proceeding in respect
     of which indemnification or contribution may be sought hereunder (whether
     or not the indemnified parties are actual or potential parties to such
     claim or action) unless such settlement, compromise or consent includes an
     unconditional release of each indemnified party from all liability arising
     out of such claim, action, suit or proceeding.

          (d)  In the event that the indemnity provided in paragraph (a) or (b)
     of this Section 8 is unavailable to or insufficient to hold harmless an
     indemnified party for any reason, the Company and the Purchasers agree to
     contribute to the aggregate losses, claims, damages and liabilities
     (including legal or other expenses reasonably incurred in connection with
     investigating or defending same) (collectively "Losses") to which the
     Company and one or both Purchasers may be subject in such proportion as is
     appropriate to reflect the relative benefits received by the Company and by
     the Purchasers from the offering of the Securities; provided, however, that
                                                         --------  -------      
     in no case shall a Purchaser be responsible for any amount in excess of the
     purchase discount or commission applicable to the Securities purchased by
     such Purchaser hereunder.  If the allocation provided by the immediately
     preceding sentence is unavailable for any reason, the Company and the
     Purchasers shall contribute in such proportion as is appropriate to reflect
     not only such relative benefits but also the relative fault of the Company
     and of the Purchasers in connection with the statements or omissions that
     resulted in such Losses as well

                                       26

 
     as any other relevant equitable considerations.  Benefits received by the
     Company shall be deemed to be equal to the total net proceeds from the
     offering (before deducting expenses), and benefits received by the
     Purchasers shall be deemed to be equal to the total purchase discounts and
     commissions, in each case as set forth on the cover page of the Final
     Memorandum.  Relative fault shall be determined by reference to whether any
     alleged untrue statement or omission relates to information provided by the
     Company or the Purchasers.  The Company and the Purchasers agree that it
     would not be just and equitable if contribution were determined by pro rata
     allocation or any other method of allocation that does not take account of
     the equitable considerations referred to above.  Notwithstanding the
     provisions of this paragraph (d), no person guilty of fraudulent
     misrepresentation (within the meaning of Section 11(f) of the Act) shall be
     entitled to contribution from any person who was not guilty of such
     fraudulent misrepresentation.  For purposes of this Section 8, each person
     who controls a Purchaser within the meaning of either the Act or the
     Exchange Act and each director, officer, employee and agent of a Purchaser
     shall have the same rights to contribution as such Purchaser, and each
     person who controls the Company within the meaning of either the Act or the
     Exchange Act and each officer and director of the Company shall have the
     same rights to contribution as the Company, subject in each case to the
     applicable terms and conditions of this paragraph (d).

          9.   Termination.  This Agreement shall be subject to termination in
               -----------                                                    
the absolute discretion of the Purchasers, by notice given to the Company prior
to delivery of and payment for the Securities, if prior to such time (i) trading
in the Company's Common Stock shall have been suspended by the Commission or the
National Association of Securities Dealers Automated Quotation National Market
System ("NMS") (other than by reason of an event listed in Clauses (ii), (iii)
or (iv) of this Section 9), (ii) trading in securities generally on the New York
Stock Exchange or the NMS shall have been suspended or limited or minimum prices
shall have been established on either of such Exchange or NMS, (iii) a banking
moratorium shall have been declared either by Federal or New York State
authorities or (iv) there shall have occurred any outbreak or escalation of
hostilities, declaration by the United States of a national emergency or war or
other calamity or crisis the effect of which on financial markets is such as to
make it, in the reasonable judgment of the Purchasers, impracticable or
inadvisable to proceed with the offering or delivery of the Securities as
contemplated by the Final Memorandum (exclusive of any amendment or supplement
thereof or thereto).

          10.  Representations and Indemnities to Survive.  The respective
               ------------------------------------------                 
agreements, representations, warranties, indemnities and other statements of the
Company or its officers and of the Purchasers set forth in or made pursuant to
this Agreement will

                                       27

 
remain in full force and effect, regardless of any investigation made by or on
behalf of the Purchasers or the Company or any of the officers, directors or
controlling persons referred to in Section 8 hereof, and will survive delivery
of and payment for the Securities.  The provisions of Sections 7 and 8 hereof
shall survive the termination or cancellation of this Agreement.

          11.  Notices.  All communications hereunder will be in writing and
               -------                                                      
effective only on receipt, and, if sent to the Purchasers, will be mailed,
delivered or telefaxed and confirmed to it in writing, at Seven World Trade
Center, New York, New York, 10048, telefax no.: (212) 783-2274, attention of
Legal Department; or, if sent to the Company, will be mailed, delivered or
telefaxed and confirmed to it in writing at 9255 Deering Avenue, Chatsworth,
California 91311, telefax no.: (818) 886-8756, attention of Chief Executive
Officer.

          12.  Successors.  This Agreement will inure to the benefit of and be
               ----------                                                     
binding upon the parties hereto and their respective successors and the officers
and directors and controlling persons referred to in Section 8 hereof, and no
other person will have any right or obligation hereunder.

          13.  Applicable Law.  This Agreement will be governed by and construed
               --------------                                                   
in accordance with the laws of the State of New York without regard to the
conflicts of law provisions thereof.

                                       28


 
          If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us the enclosed duplicate hereof, whereupon
this letter and your acceptance shall represent a binding agreement between the
Company and the Purchasers.


                                  Very truly yours,

                                  PLASMA & MATERIALS TECHNOLOGIES, INC.,


                                  By: /s/ Gregor A. Campbell
                                     ---------------------------
                                     Name: Gregor A. Campbell

                                     Title: President and 
                                            Chief Executive Officer


The foregoing Agreement is hereby 
confirmed and accepted as of the 
date first above written.

SALOMON BROTHERS INC
UNTERBERG HARRIS

By:  Salomon Brothers Inc


     By: /s/ Douglas A. Brengel
         ----------------------

     Its: Managing Director

                                       29

 
                                                                       EXHIBIT A


                         Form of Investment Letter for
                         -----------------------------
                      Institutional Accredited Investors
                      ----------------------------------



Plasma & Materials Technologies, Inc.
9255 Deering Avenue
Chatsworth, California 91311

Salomon Brothers Inc
Seven World Trade Center
New York, New York 10048


Dear Sirs:

          In connection with our proposed purchase of $            aggregate
principal amount of the 7-1/8% Convertible Subordinated Notes Due 2001 (the
"Securities") of Plasma & Materials Technologies, Inc., a California corporation
(the "Company"), we confirm that:

          1.   We understand that the Securities and the Common Stock issuable
     upon conversion thereof have not been registered under the Securities Act
     of 1933, as amended (the "Securities Act"), and may not be sold except as
     permitted in the following sentence.  We understand and agree, on our own
     behalf and on behalf of any accounts for which we are acting as hereinafter
     stated, (x) that such Securities are being offered only in a transaction
     not involving any public offering within the meaning of the Securities Act,
     (y) that if we should resell, pledge or otherwise transfer such Securities
     or the Common Stock issuable upon conversion thereof within three years
     after the date of the original issuance of the Securities or within three
     months after we cease to be an Affiliate (within the meaning of Rule 144A
     under the Securities Act) of the Company, such Securities or the Common
     Stock issuable upon conversion thereof may be resold, pledged or
     transferred only (i) to the Company, (ii) so long as the Securities or the
     Common Stock issuable upon conversion thereof are eligible for resale
     pursuant to Rule 144A under the Securities Act ("Rule 144A"), to a person
     whom we reasonably believe is a "qualified institutional buyer" (as defined
     in Rule 144A) ("QIB") that purchases for its own account or for the account
     of a QIB to whom notice is given that the resale, pledge or transfer is
     being made in reliance on Rule 144A (as indicated by the box checked by the
     transferor on the Certificate of Transfer on the reverse of the certificate
     for the Securities or the Common Stock issuable upon conversion thereof),
     (iii) in an offshore transaction in accordance with Regulation S under the

                                       30

 
     Securities Act (as indicated by the box checked by the transferor on the
     Certificate of Transfer on the reverse of the certificate for the
     Securities or the Common Stock issuable upon conversion thereof), (iv) to
     an institution that is an "Accredited Investor" as defined in Rule
     501(a)(1), (2), (3) or (7) under the Securities Act (as indicated by the
     box checked by the transferor on the Certificate of Transfer on the reverse
     of the certificate for the Securities or the Common Stock issuable upon
     conversion thereof) that has certified to the Company and the Trustee (or,
     in the case of Common Stock, the Transfer Agent) that it is such an
     accredited investor and is acquiring the Securities or the Common Stock
     issuable upon conversion thereof for investment purposes and not for
     distribution, (v) pursuant to an exemption from registration under the
     Securities Act provided by Rule 144 (if applicable) under the Securities
     Act, or (vi) pursuant to an effective registration statement under the
     Securities Act, in each case in accordance with any applicable securities
     laws of any state of the United States, and we will notify any purchaser of
     the Securities or the Common Stock issuable upon conversion thereof from us
     of the above resale restrictions, if then applicable.  We further
     understand that, in connection with any transfer of the Securities or
     Common Stock issuable upon conversion thereof by us, the Company and the
     Trustee (or, in the case of Common Stock, the Transfer Agent) may request,
     and if so requested we will furnish, such certificates, legal opinions and
     other information as they may reasonably require to confirm that any such
     transfer complies with the foregoing restrictions.

          2.   We are able to fend for ourselves in the transactions
     contemplated by this Offering Memorandum, we have such knowledge and
     experience in financial and business matters as to be capable of evaluating
     the merits and risks of our investment in the Securities, and we and any
     accounts for which we are acting are each able to bear the economic risk of
     our or its investment and can afford the complete loss of such investment.

          3.   We understand that the minimum principal amount of Securities
     that may be purchased by an institutional "accredited investor" (as defined
     in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the Securities
     Act) is $250,000.

          4.   We understand that the Company, Salomon Brothers Inc and
     Unterberg Harris as the initial purchasers of the Securities ("Initial
     Purchasers") and others will rely upon the truth and accuracy of the
     foregoing acknowledgements, representations and agreements and we agree
     that if any of the acknowledgements, representations and warranties deemed
     to have been made by us by our purchase of Securities, for our own account
     or for one or more accounts as to each of which we exercise sole investment
     discretion, are no longer

                                       31

 
     accurate, we shall promptly notify the Company and the Initial Purchasers.

          5.   We are acquiring the Securities purchased by us for investment
     purposes, and not for distribution, for our own account or for one or more
     accounts as to each of which we exercise sole investment discretion and we
     are or such account is an institutional "accredited investor" (as defined
     in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the Securities
     Act).

          6.   You are entitled to rely upon this letter and you are irrevocably
     authorized to produce this letter or a copy hereof to any interested party
     in any administrative or legal proceeding or official inquiry with respect
     to the matters covered hereby.


                                  Very truly yours,



                                  ______________________________
                                  (Name of Purchaser)

                                  By:___________________________

                                  Date:_________________________

                                       32

 
                                                                       EXHIBIT B

                              NOTICE TO INVESTORS


Offers and Sales by the Initial Purchasers
- ------------------------------------------

          The Securities and the Common Stock issuable upon conversion thereof
have not been registered under the Securities Act and may not be offered or sold
in the United States or to, or for the account or benefit of, U.S. persons
except in accordance with an applicable exemption from the registration
requirements thereof.  Accordingly, the Securities are being offered and sold
only (1) in the United States to qualified institutional buyers ("Qualified
Institutional Buyers") under Rule 144A under the Securities Act and to a limited
number of other institutional "accredited investors" (as defined in Rule
501(a)(1), (2), (3) or (7) under the Securities Act) ("Institutional Accredited
Investors") in a private sale exempt from the registration requirements of the
Securities Act, and (2) outside the United States to non-U.S. persons ("foreign
purchasers") in reliance upon Regulation S under the Securities Act.  Each
Institutional Accredited Investor that is a purchaser of Securities from the
Initial Purchasers will be required to sign a certificate in the form of Exhibit
A attached hereto.  Each foreign purchaser that is a purchaser of Securities
from the Initial Purchasers (an "Initial Foreign Purchaser") will be required to
sign a certificate in the form provided by the Initial Purchasers.


Investor Representations and Restrictions on Resale
- ---------------------------------------------------

          Each purchaser of the Securities will be deemed to have represented
and agreed as follows:

          (1)  it is acquiring the Securities for its own account or for an
     account with respect to which it exercises sole investment discretion, and
     that it or such account is a Qualified Institutional Buyer, an
     Institutional Accredited Investor acquiring the Securities for investment
     purposes and not for distribution or a foreign purchaser outside the United
     States;

          (2)  it acknowledges that the Securities and the Common Stock issuable
     upon conversion thereof have not been registered under the Securities Act
     and may not be sold except as permitted below;

          (3)  it understands and agrees (x) that such Securities are being
     offered only in a transaction not involving any public offering within the
     meaning of the Securities Act, and (y) that (A) if within three years (or
     such shorter period as may then be applicable under the Securities Act
     regarding the holding period for securities under Rule 144(k) of the
     Securities Act or any successor rule) after

                                       33

 
     the date of original issuance of the Securities or if within three months
     after it ceases to be an affiliate (within the meaning of Rule 144 under
     the Securities Act) of the Company, it decides to resell, pledge or
     otherwise transfer such Securities or the Common Stock issuable upon
     conversion thereof on which the applicable legend as set forth below
     appears, such Securities or the Common Stock issuable upon conversion
     thereof may be resold, pledged or transferred only (i) to the Company, (ii)
     so long as such Security or the Common Stock issuable upon conversion
     thereof is eligible for resale pursuant to Rule 144A, to a person whom the
     seller reasonably believes is a Qualified Institutional Buyer that
     purchases for its own account or for the account of a Qualified
     Institutional Buyer to whom notice is given that the resale, pledge or
     transfer is being made in reliance on Rule 144A (as indicated by the box
     checked by the transferor on the Certificate of Transfer on the reverse of
     the Security if such Security is not in book-entry form) and a certificate
     which may be obtained from the Company or the Trustee is delivered by the
     transferee to the Company and the Trustee, (iii) in an offshore transaction
     in accordance with Regulation S (as indicated by the box checked by the
     transferor on the Certificate of Transfer on the reverse of the Security if
     such Security is not in book-entry form), but, if such transfer is being
     effected by an Initial Foreign Purchaser or any foreign purchaser who has
     purchased Securities from an Initial Foreign Purchaser or from any person
     other than a Qualified Institutional Buyer or an Institutional Accredited
     Investor pursuant to this clause (iii) prior to the expiration of the "40
     day restricted period" (within the meaning of Rule 903(c)(3) of Regulation
     S under the Securities Act), the transferee shall have certified to the
     Company and the Trustee that such transferee is a non-U.S. person (within
     the meaning of Regulation S) and that such transferee is acquiring the
     Securities in an offshore transaction; (iv) to an Institutional Accredited
     Investor (as indicated by the box checked by the transferor on the
     Certificate of Transfer on the reverse of the Security if such Security is
     not in book-entry form) who has certified to the Company and the Trustee
     (or, in the case of Common Stock, the Transfer Agent) that such transferee
     is an Institutional Accredited Investor and is acquiring the Securities or
     Common Stock for investment purposes and not for distribution (provided
     that no Initial Foreign Purchaser or any foreign purchaser who has
     purchased Securities from an Initial Foreign Purchaser or from any person
     other than a Qualified Institutional Buyer or an Institutional Accredited
     Investor pursuant to clause (iii) shall be permitted to transfer any
     Securities (or the Common Stock issuable upon conversion thereof) so
     purchased by it to an Institutional Accredited Investor pursuant to this
     clause (iv) prior to the expiration of the "40 day restricted period" and a
     certificate which may be obtained from the Company or the Trustee is
     delivered by the transferee to the Company and the Trustee), (v) pursuant
     to

                                       34

 
     an exemption from registration under the Securities Act provided by Rule
     144 (if applicable) under the Securities Act and a certificate which may be
     obtained from the Company or the Trustee is delivered by the transferee to
     the Company and the Trustee, in each case in accordance with any applicable
     securities laws of any state of the United States, (B) the purchaser will,
     and each subsequent holder is required to, notify any purchaser of
     Securities or the Common Stock issuable upon conversion thereof from it of
     the resale restrictions referred to in (A) above, if then applicable, and
     (C) with respect to any transfer of Securities or the Common Stock issuable
     upon conversion thereof by an Institutional Accredited Investor, such
     holder will deliver to the Company and the Trustee (or, in the case of
     Common Stock, the Transfer Agent) such certificates and other information
     as they may reasonably require to confirm that the transfer by it complies
     with the foregoing restrictions, including, without limitation, a
     certificate in the form of Exhibit A hereto;

          (4)  with respect to the Securities, it understands that the
     notification requirement referred to in (3) above will be satisfied, in the
     case only of transfers by physical delivery of certificated Securities
     other than a Global Note, by virtue of the fact that the following legend
     will be placed on the Securities unless otherwise agreed by the Company:

          "THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
          1933, AS AMENDED (THE "SECURITIES ACT").  THE HOLDER HEREOF, BY
          PURCHASING THIS SECURITY, AGREES FOR THE BENEFIT OF THE COMPANY THAT
          THIS SECURITY MAY NOT BE RESOLD, PLEDGED OR OTHERWISE TRANSFERRED (X)
          PRIOR TO THE THIRD ANNIVERSARY (OR SUCH SHORTER PERIOD AS MAY THEN BE
          APPLICABLE UNDER THE SECURITIES ACT) OF THE ISSUANCE HEREOF (OR ANY
          PREDECESSOR SECURITY HERETO) OR (Y) BY ANY HOLDER THAT WAS AN
          AFFILIATE OF THE COMPANY AT ANY TIME DURING THE THREE MONTHS PRECEDING
          THE DATE OF SUCH TRANSFER, IN EITHER CASE, OTHER THAN (1) TO THE
          COMPANY, (2) SO LONG AS THIS SECURITY IS ELIGIBLE FOR RESALE PURSUANT
          TO RULE 144A UNDER THE SECURITIES ACT ("RULE 144A"), TO A PERSON WHOM
          THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER
          WITHIN THE MEANING OF RULE 144A, PURCHASING FOR ITS OWN ACCOUNT OR FOR
          THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN
          THAT THE RESALE, PLEDGE OR OTHER TRANSFER IS BEING MADE IN RELIANCE ON
          RULE 144A (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE
          CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS SECURITY) AND A
          CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE TRUSTEE IS
          DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE, (3) IN AN
          OFFSHORE TRANSACTION IN ACCORDANCE WITH REGULATION S UNDER THE
          SECURITIES ACT (AS INDICATED BY THE BOX

                                       35

 
          CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON THE
          REVERSE OF THIS SECURITY), AND, IF SUCH TRANSFER IS BEING EFFECTED BY
          CERTAIN TRANSFERORS SPECIFIED IN THE INDENTURE (AS DEFINED BELOW)
          PRIOR TO THE EXPIRATION OF THE "40 DAY RESTRICTED PERIOD" (WITHIN THE
          MEANING OF RULE 903(c)(3) OF REGULATION S UNDER THE SECURITIES ACT), A
          CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE TRUSTEE IS
          DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE, (4) TO AN
          INSTITUTION THAT IS AN "ACCREDITED INVESTOR" AS DEFINED IN RULE
          501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT (AS INDICATED BY
          THE BOX CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON
          THE REVERSE OF THIS SECURITY) THAT IS ACQUIRING THIS SECURITY FOR
          INVESTMENT PURPOSES AND NOT FOR DISTRIBUTION, AND A CERTIFICATE IN THE
          FORM ATTACHED TO THIS SECURITY IS DELIVERED BY THE TRANSFEREE TO THE
          COMPANY AND THE TRUSTEE (PROVIDED THAT CERTAIN HOLDERS SPECIFIED IN
          THE INDENTURE MAY NOT TRANSFER THIS SECURITY PURSUANT TO THIS CLAUSE
          (4) PRIOR TO EXPIRATION OF THE "40 DAY RESTRICTED PERIOD" (WITHIN THE
          MEANING OF RULE 903(c)(3) OF REGULATION S UNDER THE SECURITIES ACT),
          (5) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
          ACT PROVIDED BY RULE 144 (IF APPLICABLE) UNDER THE SECURITIES ACT AND
          A CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE TRUSTEE IS
          DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE, OR (6)
          PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES
          ACT AND A CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE
          TRUSTEE IS DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE,
          IN EACH CASE IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY
          STATE OF THE UNITED STATES OR OTHER JURISDICTIONS.  AN INSTITUTIONAL
          ACCREDITED INVESTOR HOLDING THIS SECURITY AGREES THAT IT WILL FURNISH
          TO THE COMPANY AND THE TRUSTEE SUCH CERTIFICATES AND OTHER INFORMATION
          AS THEY MAY REASONABLY REQUIRE TO CONFIRM THAT ANY TRANSFER BY IT OF
          THIS SECURITY COMPLIES WITH THE FOREGOING RESTRICTIONS.  THE HOLDER
          HEREOF, BY PURCHASING THIS SECURITY, REPRESENTS AND AGREES FOR THE
          BENEFIT OF THE COMPANY THAT IT IS (1) A QUALIFIED INSTITUTIONAL BUYER
          WITHIN THE MEANING OF RULE 144A OR (2) AN INSTITUTION THAT IS AN
          "ACCREDITED INVESTOR" AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7)
          UNDER THE SECURITIES ACT AND THAT IS HOLDING THIS SECURITY FOR
          INVESTMENT PURPOSES AND NOT FOR DISTRIBUTION OR (3) A NON-U.S. PERSON
          OUTSIDE THE UNITED STATES WITHIN THE MEANING OF (OR AN ACCOUNT
          SATISFYING THE REQUIREMENTS OF PARAGRAPH (o)(2) OF RULE 902 UNDER)
          REGULATION S UNDER THE SECURITIES ACT.";

          (5)  with respect to the Common Stock issuable upon conversion of the
     Securities, it understands that the notification requirement referred to in
     (3) above will be

                                       36

 
     satisfied by virtue of the fact that the following legend will be placed on
     the Common Stock unless otherwise agreed by the Company:

          "THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
          1933, AS AMENDED (THE "SECURITIES ACT").  THE HOLDER HEREOF, BY
          PURCHASING THIS SECURITY, AGREES FOR THE BENEFIT OF THE COMPANY THAT
          THIS SECURITY MAY NOT BE RESOLD, PLEDGED OR OTHERWISE TRANSFERRED (X)
          PRIOR TO THE THIRD ANNIVERSARY (OR SUCH SHORTER PERIOD AS MAY THEN BE
          APPLICABLE UNDER THE SECURITIES ACT) OF THE ISSUANCE HEREOF (OR ANY
          PREDECESSOR SECURITY HERETO) OR (Y) BY ANY HOLDER THAT WAS AN
          AFFILIATE OF THE COMPANY AT ANY TIME DURING THE THREE MONTHS PRECEDING
          THE DATE OF SUCH TRANSFER, IN EITHER CASE, OTHER THAN (1) TO THE
          COMPANY, (2) SO LONG AS THIS SECURITY IS ELIGIBLE FOR RESALE PURSUANT
          TO RULE 144A UNDER THE SECURITIES ACT ("RULE 144A"), TO A PERSON WHOM
          THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER
          WITHIN THE MEANING OF RULE 144A, PURCHASING FOR ITS OWN ACCOUNT OR FOR
          THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN
          THAT THE RESALE, PLEDGE OR OTHER TRANSFER IS BEING MADE IN RELIANCE ON
          RULE 144A (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE
          CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS SECURITY) AND A
          CERTIFICATE WHICH MAY BE OBTAINED FROM THE COMPANY OR THE TRUSTEE IS
          DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE TRUSTEE, (3) IN AN
          OFFSHORE TRANSACTION IN ACCORDANCE WITH REGULATION S UNDER THE
          SECURITIES ACT (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON
          THE CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS SECURITY), AND, IF
          SUCH TRANSFER IS BEING EFFECTED BY CERTAIN TRANSFERORS SPECIFIED IN
          THE INDENTURE (AS DEFINED BELOW) PRIOR TO THE EXPIRATION OF THE "40
          DAY RESTRICTED PERIOD" (WITHIN THE MEANING OF RULE 903(c)(3) OF
          REGULATION S UNDER THE SECURITIES ACT), A CERTIFICATE WHICH MAY BE
          OBTAINED FROM THE COMPANY OR THE TRUSTEE IS DELIVERED BY THE
          TRANSFEREE TO THE COMPANY AND THE TRUSTEE, (4) TO AN INSTITUTION THAT
          IS AN "ACCREDITED INVESTOR" AS DEFINED IN RULE 501(a)(1), (2), (3) OR
          (7) UNDER THE SECURITIES ACT (AS INDICATED BY THE BOX CHECKED BY THE
          TRANSFEROR ON THE CERTIFICATE OF TRANSFER ON THE REVERSE OF THIS
          SECURITY) THAT IS ACQUIRING THIS SECURITY FOR INVESTMENT PURPOSES AND
          NOT FOR DISTRIBUTION, AND A CERTIFICATE IN THE FORM ATTACHED TO THIS
          SECURITY IS DELIVERED BY THE TRANSFEREE TO THE COMPANY AND THE
          TRANSFER AGENT, (5) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER
          THE SECURITIES ACT PROVIDED BY RULE 144 (IF APPLICABLE) UNDER THE
          SECURITIES ACT AND A CERTIFICATE WHICH MAY BE OBTAINED FROM THE
          COMPANY OR THE TRUSTEE IS DELIVERED BY THE TRANSFEREE TO THE COMPANY
          AND THE TRUSTEE, OR (6) PURSUANT TO AN EFFECTIVE REGISTRATION
          STATEMENT UNDER

                                       37

 
          THE SECURITIES ACT AND A CERTIFICATE WHICH MAY BE OBTAINED FROM THE
          COMPANY OR THE TRUSTEE IS DELIVERED BY THE TRANSFEREE TO THE COMPANY
          AND THE TRUSTEE, IN EACH CASE IN ACCORDANCE WITH ANY APPLICABLE
          SECURITIES LAWS OF ANY STATE OF THE UNITED STATES OR OTHER
          JURISDICTIONS.  AN INSTITUTIONAL ACCREDITED INVESTOR HOLDING THIS
          SECURITY AGREES THAT IT WILL FURNISH TO THE COMPANY AND THE TRANSFER
          AGENT SUCH CERTIFICATES AND OTHER INFORMATION AS THEY MAY REASONABLY
          REQUIRE TO CONFIRM THAT ANY TRANSFER BY IT OF THIS SECURITY COMPLIES
          WITH THE FOREGOING RESTRICTIONS.  THE HOLDER HEREOF, BY PURCHASING
          THIS SECURITY, REPRESENTS AND AGREES FOR THE BENEFIT OF THE COMPANY
          THAT IT IS (1) A QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF
          RULE 144A OR (2) AN INSTITUTION THAT IS AN "ACCREDITED INVESTOR" AS
          DEFINED IN RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT
          AND THAT IS HOLDING THIS SECURITY FOR INVESTMENT PURPOSES AND NOT FOR
          DISTRIBUTION OR (3) A NON-U.S. PERSON OUTSIDE THE UNITED STATES WITHIN
          THE MEANING OF (OR AN ACCOUNT SATISFYING THE REQUIREMENTS OF PARAGRAPH
          (o)(2) OF RULE 902 UNDER) REGULATION S UNDER THE SECURITIES ACT.";

          (6)  it (i) is able to fend for itself in the transactions
     contemplated by this Offering Memorandum; (ii) has such knowledge and
     experience in financial and business matters as to be capable of evaluating
     the merits and risks of its prospective investment in the Securities; and
     (iii) has the ability to bear the economic risks of its prospective
     investment and can afford the complete loss of such investment;

          (7)  it understands the Company, the Initial Purchasers and others
     will rely upon the truth and accuracy of the foregoing acknowledgements,
     representations and agreements and agrees that if any of the
     acknowledgements, representations and warranties deemed to have been made
     by it by its purchase of the Securities are no longer accurate, it shall
     promptly notify the Company and the Initial Purchasers. If it is acquiring
     the Securities as a fiduciary or agent for one or more investor accounts,
     it represents that it has sole investment discretion with respect to each
     such account and it has full power to make the foregoing acknowledgements,
     representations and agreements on behalf of such account; and

          (8)  it has not engaged in, and prior to the expiration of the 40-
     day period provided for in Rule 903 of Regulation S will not engage in, any
     short selling of any equity issued by the Company (including, without
     limitation, the Common Stock) or any hedging transaction with respect to
     any such equity security, including without limitation put, call or other
     option transactions, option writing and equity swaps.

                                       38

 
           (Letterhead of officer, director or major shareholder of

                     Plasma & Materials Technologies, Inc.

                     Plasma & Materials Technologies, Inc.
                  Offering of 7-1/8% Convertible Subordinated
                  -------------------------------------------
                                Notes Due 2001
                                --------------


                                                                          , 1996



Salomon Brothers Inc
Unterberg Harris
c/o Salomon Brothers Inc
Seven World Trade Center
New York, New York 10048

Dear Sirs:

          This letter is being delivered to you in connection with the proposed
Purchase Agreement (the "Purchase Agreement"), between Plasma & Materials
Technologies, Inc., a California corporation (the "Company"), and you as
purchasers relating to an offering of the Company's 7-1/8% Convertible
Subordinated Notes Due 2001, which are convertible into Common Stock, no par
value (the "Common Stock"), of the Company.

          In order to induce you to enter into the Purchase Agreement, the
undersigned agrees not to offer, sell or contract to sell, or otherwise dispose
of, directly or indirectly, or announce an offering of, any shares of Common
Stock beneficially owned by the undersigned or any securities convertible into,
or exchangeable for, shares of Common Stock for a period of 90 days following
the day on which the Purchase Agreement is executed without Salomon Brothers
Inc's; provided, however, that the undersigned may exercise any outstanding
stock options without such prior written consent.

          If for any reason the Purchase Agreement shall be terminated prior to
the Closing Date (as defined in the Purchase Agreement), the agreement set forth
above shall likewise be terminated.

                                  Yours very truly,


                                  -----------------------------------
                                  Gregor A. Campbell


 
                                  -----------------------------------
                                  John A. Rollwagon

                                       39

 
                                  -----------------------------------
                                  James F. Marshall


                                  ----------------------------------- 
                                  John W. LaValle


                                  ----------------------------------- 
                                  Harvey J. Frye


                                  -----------------------------------
                                  Steve Rhoades


                                  ----------------------------------- 
                                  David J. Hemker, M.D.


                                  ----------------------------------- 
                                  Robert J. Snyder


                                  ----------------------------------- 
                                  Craig S. Montesanti


                                  ----------------------------------- 
                                  C. Bradford Jones


                                  ----------------------------------- 
                                  Brian D. Jacobs

                                  ST. PAUL VENTURE CAPITAL, INC.


                                  By:________________________________

                                  BRENTWOOD ASSOCIATES


                                  By:________________________________

                                       40

 
                                  SCHEDULE I


                                                      Principal Amount
                                                      of Firm Securities
                                                      to be Purchased
                                                      ---------------
                                                   
Salomon Brothers Inc.................................  $60,000,000

Unterberg Harris.....................................   15,000,000
                                                       -----------

TOTAL................................................  $75,000,000
                                                       ===========


                                       41