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                                                                   Exhibit 10.49

                                    GUARANTY

         THIS GUARANTY, dated as of December 26, 1997, is executed by LAM
RESEARCH CORPORATION, a Delaware corporation ("Guarantor"), in favor of ABN AMRO
BANK N.V., acting as representative (in such capacity, "Representative
Purchaser") for the financial and other institutions which are from time to time
the parties to the Purchase Agreement referred to in Recital A below
(collectively, the "Purchasers").


                                    RECITALS

         A. At the request of Guarantor, Representative Purchaser, acting
through its Tokyo Branch, and the Purchasers have entered into a Receivables
Purchase Agreement dated as of December 26, 1997 (the "Purchase Agreement") with
Lam Research Company, Ltd., a Japanese corporation which is a wholly-owned
subsidiary of Guarantor ("Seller"), pursuant to which (i) Purchasers have agreed
to purchase from Seller certain accounts, promissory notes and other obligations
payable to Seller ("Receivables") upon the terms and subject to the conditions
set forth in the Purchase Agreement and (ii) Seller has agreed to act as
collection agent for the Receivables so purchased by Purchasers from Seller (the
"Purchased Receivables").

         B. Purchasers' obligation to purchase any Receivables from Seller under
the Purchase Agreement is subject, among other conditions, to receipt by
Purchasers of this Guaranty, duly executed by Guarantor.


                                    AGREEMENT

         NOW, THEREFORE, in consideration of the above recitals and for other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, Guarantor hereby agrees with Representative Purchaser, for itself
and for the ratable benefit of the Purchasers, as follows:

         1.       DEFINITIONS AND INTERPRETATION.

                  (a) Definitions. Unless otherwise indicated in this Guaranty,
         each term set forth in Schedule 1, when used in this Guaranty, shall
         have the respective meaning given to that term in Schedule 1 or in the
         provision of this Guaranty referenced in Schedule 1.


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                  (b) Other Interpretive Provisions. Headings in this Guaranty
         are for convenience of reference only and are not part of the substance
         hereof. All terms defined in this Guaranty in the singular form shall
         have comparable meanings when used in the plural form and vice versa.
         This Guaranty shall be governed by and construed in accordance with the
         laws of the State of California without reference to conflicts of law
         rules. References in this Guaranty to any document, instrument or
         agreement (i) shall include all exhibits, schedules and other
         attachments thereto, (ii) shall include all documents, instruments or
         agreements issued or executed in replacement thereof and (iii) shall
         mean such document, instrument or agreement, or replacement or
         predecessor thereto, as amended, modified and supplemented from time to
         time and in effect at any given time.

         2. CONTINUING GUARANTY. Guarantor unconditionally guarantees and
promises to pay and perform as and when due, upon the demand of Representative
Purchaser, all obligations of Seller under the Purchase Agreement and all other
documents, instruments and agreements delivered to Representative Purchaser or
the Purchasers in connection therewith (collectively, including this Guaranty,
the "Transaction Documents"), including (a) the obligations of Seller to
repurchase Purchased Receivables (whether pursuant to Part 7 or Part 12 of the
Purchase Agreement or otherwise), (b) the obligations of Seller as collection
agent under the Purchase Agreement (whether pursuant to Part 9 of the Purchase
Agreement or otherwise) and (c) all other obligations of Seller under the
Transaction Documents (all such obligations, including the obligations described
in clauses (a) and (b) above, to be referred to herein collectively as the
"Guaranteed Obligations"). Guarantor shall make all payments required hereunder
to Representative Purchaser, or its order, for itself and for the ratable
benefit of the Purchasers, at Representative Purchaser's office located at the
address set forth in subparagraph 8(a) hereof, or at such other office as
Representative Purchaser may designate, on demand in such lawful currency as is
required by subparagraph 8(d) hereof. Notwithstanding any termination of this
Guaranty in accordance with paragraph 6 hereof, this Guaranty shall continue to
be in full force and effect and applicable to any Guaranteed Obligations arising
thereafter which arise because prior payments of Guaranteed Obligations are
rescinded or otherwise required to be surrendered by Representative Purchaser or
the Purchasers after receipt. The liability of Guarantor hereunder is
independent of the obligations of Seller and the obligors under the Receivables
("Buyers"), and a separate action or actions may be brought and prosecuted
against Guarantor irrespective of whether action is brought against Seller, any
Buyer or any other 

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guarantor of the Guaranteed Obligations or whether Seller, any Buyer or any
other guarantor of the Guaranteed Obligations is joined in any such action or
actions. This Guaranty is a guaranty of payment and not of collection.

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         3. REPRESENTATIONS AND WARRANTIES. Guarantor represents and warrants to
Representative Purchaser and the Purchasers, as of the date hereof, the date
each Receivable is purchased pursuant to the Purchase Agreement and each other
date on which Seller makes (pursuant to Clause 12.1 of the Purchase Agreement or
otherwise) the representations and warranties set forth in the Sixth Schedule to
the Purchase Agreement, that (a) each of Guarantor and Seller is a corporation
duly organized, validly existing and in good standing under the laws of its
jurisdiction of incorporation and is duly qualified and in good standing in each
jurisdiction where the nature of its business or properties requires such
qualification, except where the failure to qualify could not have a Material
Adverse Effect; (b) the execution, delivery and performance by Guarantor and
Seller of this Guaranty and the other Transaction Documents are within the power
of Guarantor and Seller and have been duly authorized by all necessary actions
on the part of Guarantor and Seller; (c) this Guaranty and the other Transaction
Documents have been duly executed and delivered by Guarantor and Seller and
constitute legal, valid and binding obligations of Guarantor and Seller,
enforceable against them in accordance with their terms, except as limited by
bankruptcy, insolvency or other laws of general application relating to or
affecting the enforcement of creditors' rights generally; (d) the execution,
delivery and performance of this Guaranty and the other Transaction Documents do
not (i) violate any Requirement of Law, (ii) contravene any material Contractual
Obligation, or (iii) result in the creation or imposition of any Lien upon any
property, asset or revenue of Guarantor or Seller; (e) no consent, approval,
order or authorization of, or registration, declaration or filing with, any
Governmental Authority or other Person (including, without limitation, the
shareholders of any Person) is required in connection with the execution,
delivery and performance of this Guaranty and the other Transaction Documents,
except such consents, approvals, orders, authorizations, registrations,
declarations and filings that are so required and which have been obtained and
are in full force and effect; (f) each of Guarantor and Seller has paid all
taxes and other charges imposed by any Governmental Authority due and payable by
Guarantor or Seller other than those which are being challenged in good faith by
appropriate proceedings and for which adequate reserves have been established;
(g) neither Guarantor nor Seller is in violation of any Requirement of Law or
Contractual Obligation other than those the consequences of which could not have
a Material Adverse Effect; (h) the financial statements of Guarantor and Seller
which have been delivered to Representative Purchaser and the Purchasers fairly
present the respective financial positions and results of Guarantor and Seller
for the periods and as of the dates covered thereby; (i) no litigation,
investigation or proceeding of any Governmental Authority is pending or, to the

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knowledge of Guarantor, threatened against Guarantor or Seller which, if
adversely determined, could have a Material Adverse Effect; (j) Seller is a
wholly-owned subsidiary of Guarantor; (k) the obligations of Guarantor hereunder
rank at least pari passu with all other unsecured debt of Guarantor; and (l) no
event or condition which could have a Material Adverse Effect has occurred or
arisen and is continuing.

         4. COVENANTS. Until the Purchase Agreement is terminated and all
Purchased Receivables are paid in full, Guarantor hereby agrees (a) to deliver
to Representative Purchaser and the other Purchasers (i) within 55 days after
the last day of each of its fiscal quarters, its financial statements for such
quarter, (ii) within 100 days after the last day of each of its fiscal years,
its audited financial statements for such year, (iii) notice of any Potential
Termination Event, any Termination Event or any other default under the
Transaction Documents or of any other event or condition which could have a
Material Adverse Effect, and (iv) such other information regarding the business,
operations or financial or other condition of Guarantor or Seller as
Representative Purchaser or any Purchaser may reasonably request; (b) to keep,
and cause Seller to keep, proper books of record and account and to permit
Representative Purchaser or any Purchaser to examine the same; (c) to the extent
failure to do so could have a Material Adverse Effect, to comply and cause
Seller to comply with all Requirements of Law and Contractual Obligations; (d)
to maintain and cause Seller to maintain its corporate existence and all rights,
privileges and franchises necessary for the conduct of its business; (e) to
cause the obligations of Guarantor hereunder to rank at least pari passu with
all other unsecured debt of Guarantor at all times; (f) to comply with each of
the financial covenants of Guarantor (as "Borrower" therein) set forth in
Subparagraph 5.02(l) of the Credit Agreement (as such financial covenants may be
waived or amended from time to time in accordance with Paragraph 8.04 of the
Credit Agreement with the consent of the Majority Purchasers); provided,
however, that in the event the Credit Agreement ceases to be a binding
obligation on the parties thereto, the financial covenants of Guarantor (as
"Borrower" therein) most recently set forth in Subparagraph 5.02(l) of the
Credit Agreement shall be deemed to be the financial covenants of Guarantor (as
"Borrower" therein) to have been incorporated herein by this reference.

         5. AUTHORIZED ACTIONS. Guarantor authorizes each of Representative
Purchaser and each Purchaser, in its discretion, without notice to Guarantor,
irrespective of any change in the financial condition of Seller, Guarantor, any
Buyer or any other guarantor of the Guaranteed Obligations since the date
hereof, and without affecting or impairing in any way the liability of 

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Guarantor hereunder, from time to time to (a) purchase from Seller new
Receivables and create new Guaranteed Obligations, and, either before or after
receipt of notice of revocation, renew, compromise, extend, accelerate or
otherwise change the time for payment or performance of, or otherwise change the
terms of the Purchased Receivables and Guaranteed Obligations or any part
thereof, including increase or decrease of the rate of interest or discount
thereon; (b) take and hold security for the payment or performance of the
Purchased Receivables and Guaranteed Obligations and exchange, enforce, waive or
release any such security; (c) apply such security and direct the order or
manner of sale thereof; (d) purchase such security at public or private sale;
(e) otherwise exercise any right or remedy it may have against Seller,
Guarantor, any Buyer, any other guarantor of the Guaranteed Obligations or any
security, including, without limitation, the right to foreclose upon any such
security by judicial or nonjudicial sale; (f) settle, compromise with, release
or substitute any one or more makers, endorsers or guarantors of the Purchased
Receivables or Guaranteed Obligations; and (g) assign the Purchased Receivables,
the Guaranteed Obligations, this Guaranty, or the other Transaction Documents in
whole or in part.

         6. WAIVERS. Guarantor waives (a) any right to require Representative
Purchaser and the Purchasers to (i) proceed against Seller, any Buyer or any
other guarantor with respect to the Guaranteed Obligations, (ii) proceed against
or exhaust any security received from Seller, any Buyer or any other guarantor
with respect to the Guaranteed Obligations, or (iii) pursue any other remedy in
Representative Purchaser's or any Purchaser's power whatsoever; (b) any defense
arising by reason of the application by Seller of the proceeds of any purchase;
(c) any defense resulting from the absence, impairment or loss of any right of
reimbursement, subrogation, contribution or other right or remedy of Guarantor
against Seller, any Buyer, any other guarantor with respect to the Guaranteed
Obligations or any security, whether resulting from an election by
Representative Purchaser or any Purchaser to foreclose upon security by
nonjudicial sale, or otherwise; (d) any setoff or counterclaim of Seller or any
defense which results from any disability or other defense of Seller or the
cessation or stay of enforcement from any cause whatsoever of the liability of
Seller (including, without limitation, the lack of validity or enforceability of
any Transaction Document); (e) any right to exoneration of sureties which would
otherwise be applicable; (f) until all obligations of Representative Purchaser
and the other Purchasers under the Transaction Documents have been terminated
and the Guaranteed Obligations have been fully satisfied, any right of
subrogation or reimbursement and, if there are any other guarantors of the
Guaranteed Obligations, any right of contribution, and right to 


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enforce any remedy which Representative Purchaser or any Purchaser now has or
may hereafter have against Seller, and any benefit of, and any right to
participate in, any security now or hereafter received by Representative
Purchaser or any Purchaser; (g) all presentments, demands for performance,
notices of non-performance, notices delivered under the Purchase Agreement or
any other Transaction Document, protests, notice of dishonor, and notices of
acceptance of this Guaranty and of the existence, creation or incurring of new
or additional Purchased Receivables or Guaranteed Obligations and notices of any
public or private foreclosure sale; (h) the benefit of any statute of
limitations to the extent permitted by law; (i) any appraisement, valuation,
stay, extension, moratorium redemption or similar law or similar rights for
marshalling; (j) any right to be informed by Representative Purchaser or any
Purchaser of the financial condition of Seller, any Buyer or any other guarantor
with respect to the Guaranteed Obligations or any change therein or any other
circumstances bearing upon the risk of nonpayment or nonperformance of the
Purchased Receivables or Guaranteed Obligations; and (k) any right to revoke
this Guaranty prior to the termination of the Transaction Documents and the
satisfaction in full of all the Guaranteed Obligations. Guarantor has the
ability and assumes the responsibility for keeping informed of the financial
condition of Seller, the Buyers and any other guarantors of the Guaranteed
Obligations and of other circumstances affecting such nonpayment and
nonperformance risks. Without limiting the scope of any of the foregoing
waivers, Guarantor hereby waives (i) all rights and defenses arising out of an
election of remedies by Representative Purchaser or any Purchaser, even though
that election of remedies, such as a nonjudicial foreclosure with respect to
security for a Guaranteed Obligation, has destroyed Guarantor's rights of
subrogation and reimbursement against Seller by the operation of Section 580d of
the Code of Civil Procedure or otherwise, (ii) all rights and defenses Guarantor
may have by reason of protection afforded to Seller with respect to the
Guaranteed Obligations pursuant to the antideficiency or other laws of
California limiting or discharging the Guaranteed Obligations, including,
without limitation, Section 580a, 580b, 580d, or 726 of the California Code of
Civil Procedure, and (iii) all other rights and defenses available to Guarantor
by reason of Sections 2787 to 2855, inclusive, of the California Civil Code.

         7. SUBORDINATION. Guarantor hereby subordinates any obligations of
Seller to Guarantor (the "Subordinated Obligations") to the Guaranteed
Obligations as provided in this paragraph 7. Until the occurrence of a Potential
Termination Event or Termination Event, Guarantor may receive regularly
scheduled payments from Seller on account of Subordinated 



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Obligations. Upon the occurrence and during the continuance of any Potential
Termination Event or Termination Event, however:

                  (a) Representative Purchaser and the Purchasers shall be
         entitled to receive payment of all Guaranteed Obligations before
         Guarantor receives payment of any Subordinated Obligations;

                  (b) Any payments on the Subordinated Obligations, if
         Representative Purchaser or any Purchaser so requests, shall be
         collected, enforced and received by Guarantor as trustee for
         Representative Purchaser and the Purchasers and be paid over to
         Representative Purchaser on account of the Guaranteed Obligations, but
         without reducing or affecting in any manner the liability of Guarantor
         under the other provisions of this Guaranty; and

                  (c) Representative Purchaser is authorized and empowered (but
         without any obligation to so do), in its discretion, (i) in the name of
         Guarantor, to collect and enforce, and to submit claims in respect of,
         the Subordinated Obligations and to apply any amounts received thereon
         to the Guaranteed Obligations and (ii) to require Guarantor (A) to
         collect and enforce, and to submit claims in respect of, the
         Subordinated Obligations and (B) to pay any amounts received on such
         Subordinated Obligations to Representative Purchaser for application to
         the Guaranteed Obligations.

         8.       MISCELLANEOUS.

                  (a) Notices. Except as otherwise provided herein, all notices,
         requests, demands, consents, instructions or other communications to or
         upon Representative Purchaser, any Purchaser or Guarantor under this
         Guaranty shall be in writing and telecopied, mailed or delivered to
         each party at its telecopier number or address set forth below (or to
         such other telecopier number or address for any party as indicated in
         any notice given by that party to the other party) and if to any
         Purchaser to the address set forth in Exhibit 1 to the Purchase
         Agreement. All such notices and communications shall be effective (i)
         when sent by Federal Express or other overnight service of recognized
         standing, on the Business Day following the deposit with such service;
         (ii) when mailed, first class postage prepaid and addressed as
         aforesaid through the United States Postal Service, upon receipt; (iii)
         when delivered by hand, upon delivery; and (iv) when telecopied, upon
         confirmation of receipt.




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                   Representative
                    Purchaser:       ABN AMRO Bank N.V.
                    ---------
                                                    
                                     101 California Street
                                     Suite 4550
                                     San Francisco, California  94111-5812
                                     Attn:  Robert N. Hartinger
                                     Telephone:  (415) 984-3710
                                     Facsimile:  (415) 362-3524

                    Guarantor:       Lam Research Corporation
                                     47300 Bayside Parkway
                                     Fremont, California  94538
                                     Attn:  Craig Garber
                                     Telephone:  (510) 572-1875
                                     Facsimile:  (510) 572-1586


                  (b) Expenses. Guarantor shall pay on demand, whether or not
         any Receivable is purchased under the Transaction Documents, (i) all
         reasonable fees and expenses, including reasonable attorneys' fees and
         expenses, incurred by Representative Purchaser in connection with the
         preparation, execution and delivery of, and the exercise of its duties
         under, this Guaranty and the other Transaction Documents, and the
         preparation, execution and delivery of amendments and waivers hereunder
         and thereunder; and (ii) all reasonable fees and expenses, including
         reasonable attorneys' fees and expenses, incurred by Representative
         Purchaser and the Purchasers in the enforcement or attempted
         enforcement of this Guaranty or any of the Guaranteed Obligations or in
         preserving any of Representative Purchaser's or any Purchaser's rights
         and remedies (including, without limitation, all such fees and expenses
         incurred in connection with any "workout" or restructuring affecting
         the Transaction Documents or the Guaranteed Obligations or any
         bankruptcy or similar proceeding involving Guarantor, Seller or any of
         their affiliates).

                  (c) Indemnifications. To the fullest extent permitted by law,
         Guarantor agrees to protect, indemnify, defend and hold harmless
         Representative Purchaser, the Purchaser's and their affiliates and
         their respective directors, officers, employees, agents and advisors
         ("Indemnitees") from and against any and all liabilities, losses,
         damages or expenses of any kind or nature and from any and all suits,
         claims or demands (including in respect of or for reasonable attorney's
         fees and other expenses) arising on account of or in connection with
         any matter or thing or action or failure to act by Indemnitees, or any
         of them, arising out of or relating to this Guaranty or the other
         Transaction Documents, including without limitation any use by
         Guarantor of any proceeds of any Receivables purchases, except to the

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         extent such liability arises from the willful misconduct or gross
         negligence of the Indemnitees. Upon receiving knowledge of any suit,
         claim or demand asserted by a third party that Representative Purchaser
         or any Purchaser believes is covered by this indemnity, Representative
         Purchaser or such Purchaser shall give Guarantor reasonable notice of
         the matter and an opportunity to defend it, at Guarantor's sole cost
         and expense, with legal counsel satisfactory to Representative
         Purchaser or such Purchaser, as the case may be. Any failure or delay
         of Representative Purchaser or any Purchaser so to notify Guarantor of
         any such suit, claim or demand shall not relieve Guarantor of its
         obligations under this subparagraph 8(c) but shall reduce such
         obligations to the extent of any increase in those obligations caused
         solely by such failure or delay. The obligations of Guarantor under
         this subparagraph 8(c) shall survive the payment and performance of the
         Guaranteed Obligations.

                  (d)      Currency of Payment.

                       (i) Guarantor shall make all payments of the Guaranteed
                  Obligations hereunder in the currency in which such Guaranteed
                  Obligations are required to be paid by Seller pursuant to the
                  other Transaction Documents and shall make all other payments
                  hereunder in the lawful currency of the United States.

                      (ii) If any sum due from Guarantor under this Guaranty or
                  any order or judgment given or made in relation hereto has to
                  be converted from the currency (the "first currency") in which
                  the same is payable hereunder or under such order or judgment
                  into another currency (the "second currency") for the purpose
                  of (A) making or filing a claim or proof against Guarantor
                  with any Governmental Authority, (B) obtaining an order or
                  judgment in any court or other tribunal or (C) enforcing any
                  order or judgment given or made in relation hereto, Guarantor
                  shall, to the fullest extent permitted by law, indemnify and
                  hold harmless each of the Persons to whom such sum is due from
                  and against any loss suffered as a result of any discrepancy
                  between (1) the rate of exchange used for such purpose to
                  convert the sum in question from the first currency into the
                  second currency and (2) the rate or rates of exchange at which
                  such Person may, using reasonable efforts in the ordinary
                  course of business, purchase the first currency with the
                  second currency upon receipt of a sum paid to it in
                  satisfaction, in whole or in part, of any such order,
                  judgment, claim or 



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                  proof. The foregoing indemnity shall constitute a separate
                  obligation of Guarantor distinct from its other obligations
                  hereunder and shall survive the giving or making of any
                  judgment or order in relation to all or any of such
                  obligations.

                  (e) Waivers; Amendments. Any term, covenant, agreement or
         condition of this Guaranty may be amended or waived if such amendment
         or waiver is in writing and is signed by Guarantor and Representative
         Purchaser. No failure or delay by Representative Purchaser or any
         Purchaser in exercising any right hereunder shall operate as a waiver
         thereof or of any other right nor shall any single or partial exercise
         of any such right preclude any other further exercise thereof or of any
         other right. Unless otherwise specified in such waiver or consent, a
         waiver or consent given hereunder shall be effective only in the
         specific instance and for the specific purpose for which given.

                  (f) Assignments. This Guaranty shall be binding upon and inure
         to the benefit of Guarantor, Representative Purchaser and Purchasers
         and their respective successors and permitted assigns, except that
         Guarantor may not assign or transfer any of its rights or obligations
         under this Guaranty without the prior written consent of Representative
         Purchaser and the Purchasers. All references in this Guaranty to any
         Person shall be deemed to include all successors and assigns of such
         Person.

                  (g) Cumulative Rights, etc. The rights, powers and remedies of
         Representative Purchaser and the Purchasers under this Guaranty shall
         be in addition to all rights, powers and remedies given to
         Representative Purchaser and the Purchasers by virtue of any applicable
         law, rule or regulation of any Governmental Authority, the other
         Transaction Documents or any other agreement, all of which rights,
         powers, and remedies shall be cumulative and may be exercised
         successively or concurrently without impairing Representative
         Purchaser's or any Purchaser's rights hereunder.

                  (h) Payments Free of Taxes, Etc. All payments made by
         Guarantor under this Guaranty shall be made by Guarantor free and clear
         of and without deduction for any and all present and future taxes,
         levies, charges, deductions and withholdings. In addition, Guarantor
         shall pay upon demand any stamp or other taxes, levies or charges of
         any jurisdiction with respect to the execution, delivery, registration,
         performance and enforcement of this Guaranty. 



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         If any taxes, levies, charges or other amounts are required to be
         withheld from any amounts payable to Representative Purchaser or any
         Purchaser hereunder, the amounts so payable to Representative Purchaser
         and such Purchaser shall be increased to the extent necessary to yield
         to Representative Purchaser and such Purchaser (after payment of all
         such amounts) any such amounts payable hereunder in the amounts
         specified in this Guaranty. Upon request by Representative Purchaser or
         any Purchaser, Guarantor shall furnish evidence satisfactory to
         Representative Purchaser or such Purchaser that all requisite
         authorizations and approvals by, and notices to and filings with,
         governmental authorities and regulatory bodies have been obtained and
         made and that all requisite taxes, levies and charges have been paid.

                  (i) Partial Invalidity. If at any time any provision of this
         Guaranty is or becomes illegal, invalid or unenforceable in any respect
         under the law or any jurisdiction, neither the legality, validity or
         enforceability of the remaining provisions of this Guaranty nor the
         legality, validity or enforceability of such provision under the law of
         any other jurisdiction shall in any way be affected or impaired
         thereby.

                  (j) JURY TRIAL. EACH OF GUARANTOR, REPRESENTATIVE PURCHASER
         AND THE PURCHASERS, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW,
         HEREBY IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY AS TO ANY ISSUE
         RELATING HERETO IN ANY ACTION, PROCEEDING, OR COUNTERCLAIM ARISING OUT
         OF OR RELATING TO THIS GUARANTY.

                  (k) Submission to Jurisdiction. Guarantor hereby irrevocably
         and unconditionally:

                           (i) Submits for itself and its property in any legal
                  action or proceeding relating to this Guaranty, or for
                  recognition and enforcement of any judgment in respect
                  thereof, to the non-exclusive jurisdiction of the courts of
                  the State of California and the courts of the United States of
                  America for the Northern District of California, and consents
                  and agrees to suit being brought in such courts as
                  Representative Purchaser may elect;

                      (ii) Waives any objection that it may now or hereafter
                  have to the venue of any such action or proceeding in any such
                  court or that such proceeding was brought in an inconvenient
                  court and agrees not to plead or claim the same; and



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                      (iii) Agrees that nothing herein shall affect
                  Representative Purchaser's right to effect service of process
                  in any manner permitted by law, and that Representative
                  Purchaser shall have the right to bring any legal proceedings
                  (including a proceeding for enforcement of a judgment entered
                  by any of the aforementioned courts) against Guarantor in such
                  courts or in any other court or jurisdiction in accordance
                  with applicable law.


                          [The signature page follows]


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         IN WITNESS WHEREOF, Guarantor has caused this Guaranty to be executed
as of the day and year first above written.


                                      LAM RESEARCH CORPORATION



                                      By:
                                         ---------------------------------------
                                      Name: 
                                      Title: 




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                                   SCHEDULE 1

                                   DEFINITIONS


         "Buyers" shall have the meaning given to that term in subparagraph 2(a)
hereof.

         "Contractual Obligation" of any Person shall mean, any indenture, note,
security, deed of trust, mortgage, security agreement, lease, guaranty,
instrument, contract, agreement or other form of obligation or undertaking to
which such Person is a party or by which such Person or any of its property is
bound.

         "Credit Agreement" shall mean that certain Credit Agreement, dated as
of December 20, 1995, by and among Guarantor, each of the financial institutions
from time to time a party thereto (the "Lenders") and ABN AMRO Bank N.V., acting
through its San Francisco International Branch, as agent for the Lenders (as
amended and as further amended, restated or otherwise modified from time to time
in accordance with Paragraph 7.04 thereof).

         "Governmental Authority" shall mean any domestic or foreign national,
state or local government, any political subdivision thereof, any department,
agency, authority or bureau of any of the foregoing, or any other entity
exercising executive, legislative, judicial, regulatory or administrative
functions of or pertaining to government, including, without limitation, the
Federal Deposit Insurance Corporation, the Federal Reserve Board, the
Comptroller of the Currency, any central bank or any comparable authority.

         "Governmental Rule" shall mean any law, rule, regulation, ordinance,
order, code interpretation, judgment, decree, directive, guidelines, policy or
similar form of decision of any Governmental Authority.

         "Guaranteed Obligations" shall have the meaning given to that term in
subparagraph 2(a) hereof.

         "Guarantor" shall have the meaning given to that term in the
introductory paragraph hereof.

         "Guaranty" shall mean this Guaranty.

         "Lien" shall mean, with respect to any property, any security interest,
mortgage, pledge, lien, claim, charge or other encumbrance in, of, or on such
property or the income therefrom, including, without limitation, the interest of
a vendor or lessor under a conditional sale agreement, capital lease or other
title 



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retention agreement, or any agreement to provide any of the foregoing, and the
filing of any financing statement or similar instrument under the Uniform
Commercial Code or comparable law of any jurisdiction.

         "Material Adverse Effect" shall mean a material adverse effect on (a)
the business, assets, operations, prospects or financial or other condition of
Guarantor or Seller; (b) the ability of Guarantor or Seller to pay or perform
the Guaranteed Obligations in accordance with the terms of this Guaranty and the
other Transaction Documents; or (c) the rights and remedies of Representative
Purchase and the Purchasers under this Guaranty, the other Transaction
Documents, any Purchased Receivables or any related document, instrument or
agreement.

         "Person" shall mean and include an individual, a partnership, a
corporation (including a business trust), a joint stock company, an
unincorporated association, a joint venture, a trust or other entity or a
Governmental Authority.

         "Potential Termination Event" shall have the meaning given to that term
in the Purchase Agreement.

         "Purchase Agreement" shall have the meaning given to that term in
Recital A hereof.

         "Purchased Receivables" shall have the meaning given to that term in
Recital A hereof.

         "Purchaser(s)" shall have the meaning given to that term in the
introductory paragraph hereof.

         "Receivables" shall have the meaning given to that term in Recital A
hereof.

         "Representative Purchaser" shall have the meaning given to that term in
the introductory paragraph hereof.

         "Requirement of Law" applicable to any Person shall mean (a) the
Articles or Certificate of Incorporation and By-laws, Partnership Agreement or
other organizational or governing documents of such Person, (b) any Governmental
Rule applicable to such Person, (c) any license, permit, approval or other
authorization granted by any Governmental Authority to or for the benefit of
such Person and (d) any judgment, decision or determination of any Governmental
Authority or arbitrator, in each case applicable to or binding upon such Person
or any of its property or to which such Person or any of its property is
subject.

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         "Seller" shall have the meaning given to that term in Recital A hereof.

         "Subordinated Obligations" shall have the meaning given to that term in
paragraph 7 hereof.

         "Termination Event" shall have the meaning given to that term in the
Purchase Agreement.

         "Transaction Documents" shall have the meaning given to that term in
subparagraph 2(a) hereof.

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