MATTSON TECHNOLOGY ANNOUNCES AVAILABILITY OF CONFERENCE CALL TO DISCUSS ACQUISITION OF VORTEK INDUSTRIES LTD

FREMONT, Calif.- June 28, 2004 - Mattson Technology, Inc. (NASDAQ: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors, today announced that will hold a conference call on Tuesday, June 29, 2004 at 9:30 a.m. Eastern time (6:30 a.m. Pacific time) to discuss its definitive agreement to acquire Vortek Industries Ltd, a privately held developer of millisecond flash annealing technology based in Vancouver, Canada.

David L. Dutton, president and chief executive officer of Mattson Technology, and Reg Allen, chief executive officer of Vortek Industries Ltd, will be available to discuss the acquisition.

The conference call will be simultaneously available to all interested listeners via an audio webcast. For access, visit the ‘Investors’ section of Mattson’s website www.mattson.com. A replay of the call will be available on Mattson’s website for two weeks following the live broadcast.

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. Internet: www.mattson.com.