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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Dinxoc8uRc536jJ0hBzkd3RJ5160tnEOxPdZ7cutbhvPlVe2nvLyiIomxVwZy6+F
 T3xSmUqqBRCNKquBUATTsQ==

<SEC-DOCUMENT>0001106726-07-000008.txt : 20070216
<SEC-HEADER>0001106726-07-000008.hdr.sgml : 20070216
<ACCEPTANCE-DATETIME>20070216090951
ACCESSION NUMBER:		0001106726-07-000008
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070214
FILED AS OF DATE:		20070216
DATE AS OF CHANGE:		20070216

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ULTRATECH INC
		CENTRAL INDEX KEY:			0000909791
		STANDARD INDUSTRIAL CLASSIFICATION:	SPECIAL INDUSTRY MACHINERY, NEC [3559]
		IRS NUMBER:				943169580
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3050 ZANKER RD
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
		BUSINESS PHONE:		4083218835

	MAIL ADDRESS:	
		STREET 1:		3050 ZANKER RD
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ULTRATECH STEPPER INC
		DATE OF NAME CHANGE:	19930727

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			THALES FUND MANAGEMENT LLC
		CENTRAL INDEX KEY:			0001106726
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22248
		FILM NUMBER:		07629483

	BUSINESS ADDRESS:	
		STREET 1:		140 BROADWAY 45TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10005
		BUSINESS PHONE:		2125093111

	MAIL ADDRESS:	
		STREET 1:		140 BROADWAY 45TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10005
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000909791</issuerCik>
        <issuerName>ULTRATECH INC</issuerName>
        <issuerTradingSymbol>UTEK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001106726</rptOwnerCik>
            <rptOwnerName>THALES FUND MANAGEMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>140 BROADWAY 45TH FL</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10005</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>55300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.59</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2803577</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote #1</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10670</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.66</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2814247</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>see footnote #1</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person acts as Investment Manager, with full investment discretion, to Temujin Holdings Ltd. and the securities reported on this Form 4 are directly owned by Temujin Holdings Ltd. and indirectly beneficially owned by the reporting person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Avi Dreyfuss</signatureName>
        <signatureDate>2007-02-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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