April 15, 2014

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Commissioners:

We have read the statements made by Mattson Technology, Inc. (copy attached), which we understand will be filed with the Securities and Exchange Commission, pursuant to Item 4.01 of Form 8-K, as part of the Form 8-K of Mattson Technology, Inc. dated April 9, 2014. We agree with the statements concerning our Firm in such Form 8-K.

Very truly yours,

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP, 488 Almaden Boulevard, Suite 1800, San Jose, CA 95110

T: (408) 817 3700, F: (408) 817 5050, www.pwc.com/us