Exhibit 24.1

Limited Power of Attorney - Securities Law Compliance

 	This statement confirms that the undersigned, as an executive officer of KLA-Tencor Corporation
(the "Corporation"), hereby appoints Jeffrey Eisenberg (in his role as corporate assistant secretary) the
undersigned's true and lawful attorney-in-fact and agent to:

1.	complete and execute Forms ID, 3, 4 and 5 and other forms (including any
amendments thereto) as such attorney-in-fact shall in his discretion determine to be
required or advisable pursuant to Section 16 of the Securities Exchange Act of 1934 (as
amended, the "Act") and the rules and regulations promulgated thereunder, or any successor laws
and regulations, as a consequence of or in connection with the undersigned's appointment as a director
of the Corporation, the undersigned's request for filing codes from the Securities and Exchange Commission ("SEC"),
or the undersigned's ownership, acquisition or disposition of securities of the Corporation; and

2.	to do all acts necessary in order to file such forms with the SEC, or any securities exchange
or national association, that the Corporation and such other person or agency as the
attorney-in-fact shall deem appropriate.

The undersigned hereby ratifies and confirms all that said attorney-in-fact and agent
shall do or cause to be done by virtue hereof.  The undersigned acknowledges that the
foregoing attorney-in-fact, in serving in such capacity at the request of the undersigned,
is not assuming, nor is the Corporation assuming, any of the undersigned's
responsibilities to comply with the Act.  This Limited Power of Attorney shall remain in full force
and effect until the undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigned's ownership of and transactions in securities of the Corporation, unless
earlier revoked by the undersigned in a signed writing delivered to the Corporation and
the foregoing attorney-in-fact.

	This Limited Power of Attorney is executed at Milpitas, California as of the date
set forth below.

Signature: /s/ BRIAN M. MARTIN
Print Name: Brian M. Martin
Dated: February 10, 2011

Witness:

Signature: /s/ KERRY BIRD
Print Name: Kerry Bird
Dated: February 10, 2011