MATTSON TECHNOLOGY, INC. ANNOUNCES PRICING OF COMMON STOCK IN PUBLIC OFFERING

FREMONT, Calif. — February 11, 2004 — Mattson Technology, Inc. (Nasdaq: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors today announced that the underwritten public offering of 7.5 million shares of its common stock, including 3.75 million newly issued shares being sold by the Company and 3.75 million outstanding shares being sold by STEAG Electronic Systems AG, has been priced at $11.50 per share. This will result in net proceeds to the Company of approximately $40 million. The underwriters of the offering have a 30-day option to purchase an additional 562,500 shares of common stock from the Company and 562,500 shares of common stock from STEAG to cover any over-allotments. All of the shares of common stock are being offered by the company and STEAG pursuant to an effective registration statement previously filed with the Securities and Exchange Commission. JPMorgan and Citigroup are serving as the joint book-running managers for the offering, and Deutsche Bank Securities Inc. and Needham & Company, Inc. are serving as co-managers.

Copies of the final prospectus supplement and accompanying prospectus may be obtained, when available, from J.P. Morgan Securities Inc., 8th Floor, 277 Park Avenue, New York, New York 10172 and from the Prospectus Department of Citigroup Global Markets Inc., Brooklyn Army Terminal, 140 58th Street, 8th floor, Brooklyn, NY 11220.

This news release is neither an offer to sell nor the solicitation of an offer to buy the securities described herein, nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities law of any such state or jurisdiction. The offering may be made only by means of a prospectus supplement and the accompanying prospectus.

About Mattson Technology, Inc.

Mattson Technology, Inc. is a leading supplier of semiconductor wafer processing equipment used in the fabrication of integrated circuits. The company’s dry strip and RTP equipment utilize innovative technology to deliver advanced processing capabilities on high-productivity platforms for the fabrication of current- and next-generation devices. Since beginning operations in 1989, the company’s core vision has been to help bring technology leadership and productivity gains to semiconductor manufacturers worldwide. For more information, please contact Mattson Technology, Inc., 47131 Bayside Parkway, Fremont, Calif. 94538. Telephone: (800) MATTSON/(510) 657-5900. Fax: (510) 492-5911.