MATTSON TECHNOLOGY OVERTAKES NO. 1 POSITION IN DRY RESIST STRIP
Dataquest Report Culminates Company's Rapid Market Share Rise

FREMONT, Calif. — May 3, 2000 — Mattson Technology, Inc. (Nasdaq: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors, today announced it has overtaken the industry's No. 1 position among suppliers of dry resist strip systems. In a recently released market report from Dataquest Inc., a unit of Gartner Group Inc., Mattson Technology became the industry's No. 1 dry strip supplier in 1999, based on system sales. The No. 1 position culminates a rapid six-year rise in market share from below 5 percent in 1993 to nearly 30 percent in 1999.

The report from Dataquest also noted that in 1999 Mattson Technology had $63 million in dry strip system revenues - a 47 percent one-year rise in revenue. In addition, the market share gap between competitors has also widened with the nearest competitor now almost 5 percent behind Mattson.

According to Brad Mattson, Mattson Technology's CEO, the Aspen Strip's Inductively Coupled Plasma (ICP) source is a key technology differentiator. "The Aspen Strip is able to perform advanced residue removal on the most sensitive device structures with extremely high strip rates," observed Mattson. "Our ICP source technology's extendability to address design rules below 0.15 micron and new processes such as emerging low-k and copper offers a significant technological advantage."

Mattson Technology believes that in addition to its ICP source technology, the high throughput of the Aspen platform is an important factor in the decision of 17 of the top 20 equipment buyers to install Aspen Strip systems. The Aspen Strip is also widely used by foundry customers in Taiwan and Singapore. Mattson noted, "Foundry customers are some of the most demanding customers in the industry. Their value added is in process and manufacturing excellence. The fact that Taiwanese foundry customers have selected us as their main strip supplier reflects the productivity advantage our strip solutions provide over competitive 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