MATTSON TECHNOLOGY AND IMEC TO DEVELOP NEXT-GENERATION PROCESS
Joint Development Targets Future Photoresist and Residue Removal for Low-K and Copper

FREMONT, Calif. — May 15, 2000 — Mattson Technology, Inc. (Nasdaq: MTSN), a leading supplier of advanced semiconductor manufacturing process equipment, and IMEC, Europe's largest independent microelectronics research and development center, today announced that they will jointly develop new photoresist and residue removal processes. Technology and process development will take place on a dual chamber Aspen Strip system installed at IMEC's research facility in Leuven, Belgium.

To strengthen its technological leadership, Mattson Technology will team with IMEC to focus on the challenges of low-k and copper processing for devices with 0.13 micron and smaller design rules. The development and integration of new processing techniques that address the use of emerging dielectric materials is a significant technological obstacle in manufacturing semiconductors with geometries smaller than 0.15 micron. A significant challenge will be stripping photoresist on top of organic-based dielectric materials.

Mattson has worked with IMEC since 1998 to advance dry strip technologies for processing devices with 0.18 to 0.13 design rules. Serge Vanhaelemeersh, IMEC's manager of dry etch development, explained that the decision to use the Aspen Strip was due to the system's unique Inductively Coupled Plasma (ICP) source technology and IMEC's previous experience with the system. "The challenges of new low-k and copper materials demands a new, more advanced approach to cleaning," noted Vanhaelemeersh. "Our previous work with the ICP technology for resist and polymer removal development in high dose implant, poly and via strip applications for 0.18 to 0.13 micron design rules made the Aspen Strip a logical choice for this advanced strip project."

According to Brad Mattson, Mattson Technology's CEO, the joint development project offers a great opportunity to help advance technology in the semiconductor industry, as well as maintain the company's position at the leading edge of resist strip technology. "Technology gains, even incremental, are very costly. The largest expense is often incurred during the qualification and evaluation phases because they require the use of a manufacturing environment," noted Mattson. "This project will allow Mattson to team with IMEC, leveraging IMEC's wafer fab line to help quickly qualify new processes and bring strip innovations to market faster."

According to a recent Dataquest report, Mattson Technology is now clearly the dry strip market leader, based on system sales in 1999. Mattson's $63 million in strip revenue represents 27.8 percent of the market, nearly 5 percent more than the nearest supplier. Furthermore, 17 out of the world's top 20 semiconductor manufacturers have installed Aspen Strip systems.

This Press Release contains forward looking statements regarding, among other matters, industry trends and the Company's future financial performance. Forward looking statements address matters which are subject to a number of risks and uncertainties. In addition to the general risks associated with the development of complex technology, future results of the Company will depend on a variety of factors, including the timing of significant orders, the ability of the Company to bring new systems to market, the timing of new product releases by the Company's competitors, slowdowns in the semiconductor industry, and other competitive factors. Reference is made to the Company's filings with the Securities and Exchange Commission for further discussion of risks and uncertainties regarding the Company's business.

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