<SUBMISSION>
<ACCESSION-NUMBER>0001225111-03-000002
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20030729
<FILING-DATE>20030729
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>LAM RESEARCH CORP
<CIK>0000707549
<ASSIGNED-SIC>3559
<IRS-NUMBER>942634797
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0630
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>4650 CUSHING BLVD
<CITY>FREMONT
<STATE>CA
<ZIP>94538
<PHONE>5106590200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>4650 CUSHING PARKWAY
<CITY>FREMONT
<STATE>CA
<ZIP>94538
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>NEWBERRY STEPHEN G
<CIK>0001225111
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-12933
<FILM-NUMBER>03809849
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>LAM RESEARCH
<STREET2>4650 CUSHING PARKWAY
<CITY>FREMONT
<STATE>CA
<ZIP>94538
<PHONE>510 572 0200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>LAM RESEARCH
<STREET2>4650 CUSHING PARKWAY
<CITY>FREMONT
<STATE>CA
<ZIP>94538
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-07-29</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000707549</issuerCik>
        <issuerName>LAM RESEARCH CORP</issuerName>
        <issuerTradingSymbol>LRCX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001225111</rptOwnerCik>
            <rptOwnerName>NEWBERRY STEPHEN G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>LAM RESEARCH</rptOwnerStreet1>
            <rptOwnerStreet2>4650 CUSHING PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>FREMONT</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-07-29</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-07-29</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.82</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-07-29</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-07-29</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Rght to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.82</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-07-29</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2003-07-29</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.82</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>1999-03-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-11-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2390500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Additional Indirect Beneficial Ownership, Derivative Securities: 60,000 shares, a prepaid forward contract held in &quot;The Stephen &amp; Shelly Newberry Living Trust&quot;</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Sandra Blum by Power of Attorney</signatureName>
        <signatureDate>2003-07-29</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>3
<FILENAME>ex24newberry.htm
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
<TITLE>POWER OF ATTORNEY</TITLE>
</HEAD>
<BODY><B><FONT face=Arial size=2>
<P align=center>POWER OF ATTORNEY</P></B>
<P align=justify></P>
<P align=justify>Know all by these presents, that the undersigned hereby
constitutes and appoints each of <B><U>George Schisler</B>, <I>General
Counsel</I>,<B> Martin Anstice, </B><I>Corporate Controller</I><B> </B>and<B>
Sandra Blum, </B><I>Manager, Employee</I><B> </B><I>Shareholder
Services</I></U>, signing singly, the undersigned's true and lawful attorney-in-
fact to:</P>
<P align=justify></P>
<DIR>
<DIR>
<DIR>
<DIR>
<P align=justify>(1) execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of <B><U>Lam Research
Corporation</B></U> (the "Company"), Forms&nbsp;3, 4, and 5 in accordance with
Section&nbsp;16(a) of the Securities Exchange Act of 1934 and the rules
thereunder;</P>
<P align=justify></P>
<P align=justify>(2) do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and execute any such
Form&nbsp;3, 4, or 5, complete and execute any amendment or amendments thereto,
and timely file such form with the United States Securities and Exchange
Commission and any stock exchange or similar authority; and</P>
<P align=justify></P>
<P align=justify>(3) take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact, may be of
benefit to, in the best interest of, or legally required by, the undersigned, it
being understood that the documents executed by such attorney- in-fact on behalf
of the undersigned pursuant to this Power of Attorney shall be in such form and
shall contain such terms and conditions as such attorney-in- fact may approve in
such attorney-in-fact's discretion.</P>
<P align=justify></P></DIR></DIR></DIR></DIR>
<P align=justify>The undersigned hereby grants to each such attorney-in- fact
full power and authority to do and perform any and every act and thing
whatsoever requisite, necessary, or proper to be done in the exercise of any of
the rights and powers herein granted, as fully to all intents and purposes as
the undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney and the
rights and powers herein granted. The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section&nbsp;16 of the Securities
Exchange Act of 1934.</P>
<P align=justify></P>
<P align=justify>This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms&nbsp;3, 4, and 5 with
respect to the undersigned's holdings of and transactions in securities issued
by the Company, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact.</P>
<P align=justify></P>
<P align=justify>IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this<B> <U>14<SUP>th</SUP> day of March 2003.
</P></B></U>
<P align=justify></P>
<P align=justify>&nbsp;</P>
<P align=justify><U>/s/ Stephen G Newberry</P></U>
<P align=justify>Signature</P>
<P align=justify></P>
<P align=justify> Steven G Newberry</P>
<P align=justify>Print Name</P></FONT><FONT
face="Century Schoolbook,Bookman Old Style" size=2></FONT><FONT
face="Century Schoolbook,Bookman Old Style">
<P>&nbsp;</P></FONT></BODY></HTML>

</TEXT>
</DOCUMENT>
</SUBMISSION>
