<SEC-DOCUMENT>0000707549-21-000033.txt : 20210209
<SEC-HEADER>0000707549-21-000033.hdr.sgml : 20210209
<ACCEPTANCE-DATETIME>20210209115027
ACCESSION NUMBER:		0000707549-21-000033
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210205
FILED AS OF DATE:		20210209
DATE AS OF CHANGE:		20210209

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ARCHER TIMOTHY
		CENTRAL INDEX KEY:			0001343600

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-12933
		FILM NUMBER:		21604767

	MAIL ADDRESS:	
		STREET 1:		4650 CUSHING PARKWAY
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94538

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LAM RESEARCH CORP
		CENTRAL INDEX KEY:			0000707549
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				942634797
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0628

	BUSINESS ADDRESS:	
		STREET 1:		4650 CUSHING BLVD
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94538
		BUSINESS PHONE:		5106590200

	MAIL ADDRESS:	
		STREET 1:		4650 CUSHING PARKWAY
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94538
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>FORM 4
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    <issuer>
        <issuerCik>0000707549</issuerCik>
        <issuerName>LAM RESEARCH CORP</issuerName>
        <issuerTradingSymbol>LRCX</issuerTradingSymbol>
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            <rptOwnerName>ARCHER TIMOTHY</rptOwnerName>
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            <rptOwnerStreet2>4650 CUSHING PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>FREMONT</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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            <isDirector>0</isDirector>
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            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
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                <directOrIndirectOwnership>
                    <value>I</value>
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                <value>Common Stock</value>
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                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
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        <derivativeTransaction>
            <securityTitle>
                <value>Market-based Performance Restricted Stock Unit</value>
            </securityTitle>
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            <transactionDate>
                <value>2021-02-05</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>13159</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F5"/>
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            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
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                    <value>13159.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                    <value>0</value>
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                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
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                <value>145.73</value>
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                <transactionCode>M</transactionCode>
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                <transactionShares>
                    <value>4464</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>145.73</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-12-06</value>
            </expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4464.0</value>
                </underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
                    <value>32740</value>
                </sharesOwnedFollowingTransaction>
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    <footnotes>
        <footnote id="F1">On 03/01/2018, the Reporting Person received a target grant of 13,159 Market-based Performance Restricted Stock Units vesting between 0% and 150% on 03/01/2021. The performance of this award was based on the Lam Research Total Shareholder Return performance relative to the Philadelphia Semiconductor Sector Index Total Shareholder Return during the performance period of 02/01/2018 to 01/31/2021.The performance payout was approved at 150% of target.</footnote>
        <footnote id="F2">The amount reported includes shares subject to unvested restricted stock units.</footnote>
        <footnote id="F3">Represents shares that were automatically withheld upon vesting of restricted stock units to satisfy tax withholding obligations.</footnote>
        <footnote id="F4">This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 19,2020.</footnote>
        <footnote id="F5">The Market-based performance restricted stock units will vest between 0% and 150% on 03/01/2021. The performance of this award is based on the Lam Research Total Shareholder Return performance relative to the Philadelphia Semiconductor Sector Index Total Shareholder Return during the performance period of 02/01/2018 through 01/31/2021.</footnote>
        <footnote id="F6">The stock options will become exercisable over four years, a quarter on the one-year anniversary of the grant date and the remainder on a pro-rated basis on the 6th day of every month thereafter for the next 36 months.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Leign Cramer by Power of Attorney</signatureName>
        <signatureDate>2021-02-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
