MATTSON TECHNOLOGY AND TOKYO ELECTRON LTD ANNOUNCE A STRATEGIC TECHNOLOGY ALLIANCE

TOKYO and FREMONT, Calif. — April 15, 2004 —Tokyo Electron Ltd. (TEL), a global supplier of semiconductor and flat panel display production equipment, and Mattson Technology, Inc. (NASDAQ: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors, today announced a strategic technology development partnership and the successful integration of Mattson’s proven rapid thermal processing (RTP) technology with TEL’s advanced gate dielectric technology. The collaboration combines TEL’s successful Trias® SPA Plasma Processing system with Mattson’s single-wafer, RTP, low-pressure annealing (LPA) module.

The LPA module, which was designed and developed at Mattson and combined with TEL’s technology, will produce state-of-the-art gate dielectrics by combining Mattson’s expertise in RTP with TEL’s ultra-thin oxide technology and nitridation by SPA (slot plane antenna). Several modules have been placed at key customer sites. The LPA module will be manufactured by Mattson exclusively for TEL and integrated with other process modules on TEL’s Trias single-wafer platform. As part of the collaboration, TEL will provide customer support and Mattson will provide technology support for the system.

“Our joint development work with TEL is an extension of Mattson Technology's overall strategy to leverage technology alliances to develop best-of-breed products that deliver superior results on the wafer for our customers,” said Robert B. MacKnight, chief operating officer of Mattson Technology. “We expect Mattson’s and TEL’s combined expertise in transistor development to enhance our abilities to offer advanced transistor formation technologies to the industry and look forward to working with TEL on future collaboration projects.”

“Our strategic partnership with Mattson Technology not only provides our SPA tool with a competitive advantage, but also demonstrates the creativity of both companies when trying to find solutions to our customers’ unique problems,” said Clark Takenaka, general manager of TEL’s Single-Wafer Deposition Business Unit.

The next phase of the joint development partnership is expected to yield improved processes for high-k dielectrics, ultra-thin interface layers and plasma oxy-nitride films for gate and capacitor applications serving both logic and memory markets.

Trias is a registered trademark of TEL in Japan, USA, Korea, Taiwan, UK, Italy, France and Germany.

About TEL

TEL is a leading supplier of innovative semiconductor and FPD (flat panel display) production equipment worldwide. Product lines include coater/developers, thermal processing systems, dry etchers, CVD systems, wet cleaning systems, and test systems. In Japan, TEL distributes other leading edge semiconductor equipment tools, such as metrology tools or process control systems. In addition, TEL distributes high quality computer systems, semiconductor devices and electronic components of other leading suppliers, as well as computer network related products from around the world. To support this diverse product base, TEL has strategically located research & development, manufacturing, sales, and service locations all over the world. TEL is a publicly held company listed on the Tokyo Stock Exchange. http://www.tel.com

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.