MATTSON MERGER OF STEAG SEMICONDUCTOR EQUIPMENT DIVISION AND CFM TECHNOLOGIES, INC. PASSES ANTITRUST REVIEW

HSR Waiting Period Expires and German Federal Cartel Office Approves Deal

FREMONT, Calif. — September 14, 2000 — Mattson Technology, Inc. (Nasdaq: MTSN) announced all governmental antitrust notification and approval requirements are now satisfied for the proposed business merger between Mattson and the semiconductor equipment division of STEAG Electronic Systems AG, and the pending merger with CFM Technologies, Inc. (Nasdaq: CFMT). The waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 has expired for both Steag and CFM Technologies. Mattson also announced that STEAG received notification that the German Federal Cartel Office has approved the transactions.

The closing remains subject to approval by the stockholders of Mattson and CFM, and other customary closing conditions. Mattson plans to file with the SEC a Proxy Statement/Prospectus relating to the transactions within the next two weeks. The date for the Mattson and CFM stockholder meetings has not been set, and will depend upon the time required by any SEC review. A targeted close date of early January was previously announced. If approvals are obtained early, the parties plan to accelerate the close date. If closure cannot be accelerated due to tax and accounting issues, the parties have agreed to waive all other conditions, essentially fulfilling all terms of the deal except for the passage of time. This will significantly enhance the certainty of closing the transaction, meeting the expressed desire of all parties to complete this transaction as quickly as possible.

About Mattson Technology

Mattson Technology Inc., is a leading supplier of thermal, plasma and wet semiconductor processing equipment. The company's products combine advanced process technology on a high productivity platform, backed by industry-leading support. Since beginning operations in 1989, the company's core vision has been to help bring technology leadership and productivity gains to semiconductor manufacturers worldwide. Headquartered in Fremont, Calif., the company maintains sales and support centers throughout the United States, Europe, Asia/Pacific and Japan. For more information, please contact Mattson Technology Inc., 2800 Bayview Drive, Fremont, Calif. 94538. Telephone: (800) MATTSON. Fax: (510) 657-0165. Internet:www.mattson.com