Exhibit II

to

Schedule 13G

Joint Filing Agreement

The undersigned persons agree and consent to the joint filing on their behalf of this Schedule 13G dated July 10, 2015 in connection with their beneficial ownership of Mattson Technology, Inc. Each of Columbia Seligman Communications & Information Fund and Columbia Management Investment Advisers, LLC authorizes Ameriprise Financial, Inc. to execute the Schedule 13G to which this Exhibit is attached and make any necessary amendments thereto.

Ameriprise Financial, Inc.
By:	/s/ Richard Dluzniewski
	Richard Dluzniewski
	Vice President-Control and Operational Risk-Operations and Investor Services
Columbia Management Investment Advisers, LLC
By:	/s/ Amy Johnson
	Amy Johnson
Title:	COO and Managing Director
Columbia Seligman Communications & Information Fund
By:	/s/ Paul Goucher
	Paul Goucher
	Senior Vice President, Chief Legal Officer and Assistant Secretary