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                                                                     Exhibit 5.1

                        Shartsis, Friese & Ginsburg LLP
                                Eighteenth Floor
                                1 Maritime Plaza
                            San Francisco, CA  94105



                                 August 6, 1997


Lam Research Corporation
4350 Cushing Parkway
Fremont, California  94538

               Re:  Lam Research Corporation
                    Registration Statement on Form S-8
                    ----------------------------------

Ladies and Gentlemen:

          At your request, we have examined the Registration Statement on Form
S-8 (the "Registration Statement") that you intend to file with the Securities
and Exchange Commission (the "Commission") in connection with the registration
under the Securities Act of 1933, as amended (the "Securities Act"), of
5,000,000 shares (the "Shares") of common stock, par value $0.001 per share
("Common Stock"), of Lam Research Corporation (the "Company") to be issued by
the Company under the Lam Research Corporation 1997 Stock Incentive Plan (the
"Plan").

          In connection with this opinion, we have examined originals or copies,
certified or otherwise identified to our satisfaction, of (i) the Plan, (ii) the
Certificate of Incorporation of the Company and the Bylaws of the Company, (iii)
copies of certain resolutions of the Board of Directors of the Company relating
to, among other things, the Shares, the Plan and the Registration Statement,
(iv) the form of certificate representing the Common Stock and (v) such other
documents, certificates and records as we have considered necessary or
appropriate for purposes of this opinion.  In our examination, we have assumed
the legal capacity of all natural persons, the genuineness of all signatures,
the authenticity of all documents submitted to us as originals, the conformity
to original documents of all documents submitted to us as certified or
photostatic copies and the authenticity of the originals of such latter
documents.  As to any facts material to the opinion expressed herein, we have
relied

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Lam Research Corporation
August 6, 1997
Page 21

upon oral or written statements and representations of officers and other
representatives of the Company and others.

          Members of our firm are admitted to the Bar in the State of
California, and we express no opinion concerning any law other than the law of
the State of California, the Delaware General Corporation law and the federal
law of the United States.  With respect to the Delaware General Corporation Law,
we have based our opinion solely upon our examination of such laws and the rules
and regulations of the authorities, administering such laws, all as reported in
accepted unofficial compilations.

          Based upon and subject to the foregoing, and assuming (i) the valid
issuance of options pursuant to the Plan and (ii) the conformity of the
certificates representing the Shares to the form thereof examined by us and the
due execution and countersignature of such certificates, we are of the opinion
that the Shares, when issued upon exercise of options in accordance with the
terms of the Plan, will be validly issued, fully paid and nonassessable.

          We hereby consent to the filing of this opinion with the Commission as
Exhibit 5.1 to the Registration Statement.  In giving this consent, we do not
thereby admit that we are in the category of persons whose consent is required
under Section 7 of the Securities Act or the rules and regulations of the
Commission.


                                            Very truly yours,



                                            /s/ Carolyn R. Klasco
                                            ---------------------
                                            Carolyn R. Klasco

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