AMENDMENT NO. 1 TO TENDER AND SUPPORT AGREEMENT

Exhibit 4.2

AMENDMENT NO. 1 TO TENDER AND SUPPORT AGREEMENT

     This AMENDMENT NO. 1 (this “Amendment”) dated as of February 7, 2007 by and among KLA Tencor Corporation, a Delaware corporation (“Parent”), Fenway Acquisition Corporation, a Delaware corporation and a wholly-owned subsidiary of Parent (“Merger Subsidiary”), Therma-Wave, Inc., a Delaware corporation (the “Company”), and the parties listed on Annex I and Annex II (each, a “Securityholder”) to the Tender and Support Agreement dated as of January 7, 2006 by and among Parent, Merger Subsidiary, the Company and each Securityholder (the “Tender and Support Agreement”), hereby amends certain provisions of the Tender and Support Agreement. Any capitalized term that is used but not otherwise defined in this Amendment shall have the meaning given to that term in the Tender and Support Agreement.

RECITALS

     WHEREAS, the parties to the Tender and Support Agreement desire to amend the Tender and Support Agreement by amending and restating Annex I thereto, as set forth in this Amendment; and

     WHEREAS, the parties hereto have duly authorized and approved this Amendment.

     NOW THEREFORE, in consideration of the foregoing and the respective representations, warranties, covenants and agreements set forth in this Amendment and the Tender and Support Agreement, as applicable, the parties hereto hereby agree as follows:

AGREEMENT

     SECTION 1. Annex I. Annex I to the Tender and Support Agreement is hereby amended and superseded in its entirety as set forth in Annex A hereto.

     SECTION 2. Governing Law. This Amendment shall be governed by and construed in accordance with the laws of the State of Delaware, without regard to the conflicts of law rules of such state.

     SECTION 3. Counterparts; Effectiveness. This Amendment may be signed in any number of counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Amendment shall become effective when each party hereto shall have received a counterpart hereof signed by all of the other parties hereto.

     SECTION 4. Amendment. This Amendment may not be altered, amended or supplemented except by an agreement in writing signed by each of the parties hereto.

     SECTION 5. Tender and Support Agreement. Except as amended by this Amendment, the Tender and Support Agreement shall remain in full force and effect.

[signature page follows]

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed by their respective authorized officers as of the day and year first above written.

	KLA-TENCOR CORPORATION
	By:	/s/ Xxxxxxx X. Xxxx
		Name:	Xxxxxxx X. Xxxx
		Title:	Chief Financial Officer
	FENWAY ACQUISITION CORPORATION
	By:	/s/ Xxxxxxx X. Xxxx
		Name:	Xxxxxxx X. Xxxx
		Title:	President
	THERMA-WAVE, INC.
	By:	/s/ Xxxxx Xxxxxx
		Name:	Xxxxx Xxxxxx
		Title:	President and CEO

[Signature Page to Amendment]

	SECURITYHOLDERS NORTH RUN MASTER FUND, LP
	By:	North Run GP, LP, its General Partner
	By:	North Run Advisors, LLC, its General Partner
	By:	/s/ Xxxxxx X. Xxxxx
		Xxxxxx X. Xxxxx, Member
	By:	/s/ Xxxx X. Xxxxxx
		Xxxx X. Xxxxxx, Member

[Signature Page to Amendment]

	DEEPHAVEN LONG/SHORT EQUITY TRADING LTD.
	By:	Deephaven Capital Management LLC
	Its: Investment Manager

	By:	/s/ Xxxxx Xxxxxx
		Name:	Xxxxx Xxxxxx
		Title:	Chief Operating Officer

	DEEPHAVEN RELATIVE VALUE EQUITY TRADING LTD.
	By:	Deephaven Capital Management LLC
	Its: Investment Manager

	By:	/s/ Xxxxx Xxxxxx
		Name:	Xxxxx Xxxxxx
		Title:	Chief Operating Officer

[Signature Page to Amendment]

XXXXXXXX XXXXXXXXX
 

/s/ Xxxxxxxx Xxxxxxxxx  

G. XXXXXXX XXXXX, XX.
 

/s/ G. Xxxxxxx Xxxxx, Xx.  

XXXX X. X’XXXXXX
 

/s/ Xxxx X. X’Xxxxxx  

XXXXXXX XXXXXX
 

/s/ Xxxxxxx Xxxxxx  

XXX XXX XXX
 

/s/ Xxx Xxx Suh  

[Signature Page to Amendment]

XXXX WILLINGE
 

/s/ Xxxx Willinge  

XXXXX XXXXXX
 

/s/ Xxxxx Xxxxxx  

XXXXX X. XXXXXX
 

/s/ Xxxxx X. Xxxxxx  

XXXXXX DER XXXXXXXXX
 

/s/ Papken Der Xxxxxxxxx  

XXXXX XXXXXX
 

/s/ Xxxxx Xxxxxx  

[Signature Page to Amendment]

XXXXXX XXXXXXXXXX
 

/s/ Xxxxxx Xxxxxxxxxx  

XXXXX XXXXXX
 

/s/ Xxxxx Xxxxxx  

XXX X. XXXXX
 

/s/ Xxx X. Xxxxx  

XXXX XXXXXXX
 

/s/ Xxxx Xxxxxxx  

XXXX XXX
 

/s/ Xxxx Xxx  

[Signature Page to Amendment]

XXXX XXXXXXX
 

/s/ Xxxx Xxxxxxx  

XXXX XXXXXXXXXX
 

/s/ Xxxx Xxxxxxxxxx  

[Signature Page to Amendment]

ANNEX A

Securityholder		Subject Company Shares
Xxxxx Xxxxxxxxx (BOD)		—
Xxxxxxx Xxxxx (BOD)		150,807
Xxxxxxx Xxxxx (BOD)		186,631(1)
Xxxx X’Xxxxxx (BOD)		20,000
Xxxxxxx Xxxxxx (BOD)		—
Xxx Xxx (BOD)		—
Xxxx Willinge (BOD)		—
Xxxxx Xxxxxx (BOD)		—
Xxxxx Xxxxxx (BOD)		25,500
Papken Der Xxxxxxxxx (Chairman)		37,000
Papken Der Xxxxxxxxx (Chairman)		234,733(2)
Xxxxx Xxxxxx		30,599
Xxx Xxxxxxxxxx		14,275
Xxxxx Xxxxxx		5,079
Xxx Xxxxx		159,976
Xxxx Xxxxxxx		5,386
Xxxx Xxx		17,050
Xxxx Xxxxxxx		44,721
Xxxx Xxxxxxxxxx		11,460
North Run Master Fund		3,606,900

(1) Of these shares, 69,831 are held in a trust where Xx. Xxxxx is a trustee. The remaining 116,800 shares are held by a limited partnership of which Xx. Xxxxx is a general partner. Xx. Xxxxx disclaims beneficial ownership in these shares as he only has pecuniary interest in the trust and limited partnership.

(2) The shares are held in a family trust of which Mr. Der Xxxxxxxxx is a trustee. Mr. Der Xxxxxxxxx disclaims beneficial ownership in these shares as he only has pecuniary interest in the trust.