GaSonics Extends Integrated Clean Technology Leadership With PEP Iridia Follow-On Order From STMicroelectronics.

SAN JOSE, Calif.--(BUSINESS WIRE)--July 12, 1999--

GaSonics International Corp. (Nasdaq/NMS:GSNX), a leading supplier of Integrated Clean(TM) solutions, today announced it has received a follow-on order from STMicroelectronics (STM), Catania, Italy, for two of its new PEP Iridia DL(TM) systems.

GaSonics' most advanced Integrated Clean tool, the Iridia is capable of performing both photoresist and residue removal in a single chamber. With the completion of the Iridia order, the Catania site now boasts the largest installed base of PEP systems in Europe.

STM will use the Iridia systems to manufacture FLASH EPROM devices. The systems will be deployed initially for HDIS applications and later for post-etch residue removal applications that may be transferred to other STM sites worldwide. System installations are scheduled to occur in July and August.

"This marks the second order in only two months for our breakthrough Iridia technology," said GaSonics' Ash Business Unit General Manager Ken Drachnik.

"The rapid speed of this tool's acceptance on a global scale demonstrates GaSonics' ability to address the limitations of wet cleaning for advanced 0.18 micron and below photoresist and residue removal applications.

"It also bolsters our global leadership in the emerging and rapidly growing Integrated Clean market, which represents significant revenue potential for GaSonics as fabs ramp to sub-0.18-micron production."

Launched in June, the Iridia is designed to offer significant advantages over existing wet and dry solutions, including faster throughput, lower defect densities and fewer wet clean process steps. Keys to the Iridia's success are its dual plasma sources and closed-loop temperature control over the entire temperature range.

This combination enables maximum process flexibility, while providing damage- and residue-free results at high throughput. The cost of chemicals, water and waste disposal, and environmental impact are reduced, enhancing the inherent cost-of-ownership benefits from using the Iridia module on a multi-chamber PEP platform.

Management would like to remind readers that any forward looking statements in this press release are always subject to risks in this ever-changing marketplace, including the cyclicality in the markets served by the company's customers, market acceptance of new and enhanced versions of the company's products, the stability of the Asia-Pacific region, the mix of products sold, the timing of significant orders and delays, deferrals, rescheduling or cancellation of orders, the relationship of operating expenses to revenue, and the proportion of direct sales and sales through distributors. For a more detailed discussion of these and associated risks, the company refers the readers to documents filed with the Securities and Exchange Commission (SEC) from time to time, specifically, the most recent Form 10-K and Form 10-Q.

GaSonics International (Nasdaq/NMS:GSNX) is a leading global supplier of Integrated Clean solutions. GaSonics' photoresist and residue removal tools improve device performance and increase yield in semiconductor manufacturing.

GaSonics' technology leadership also includes vertical high-pressure (VHP) thermal processing for ultra-thin gate oxides and low-pressure chemical vapor deposition (LPCVD) for liquid-crystal display (LCD) manufacturing. Headquartered in San Jose, GaSonics supports its installed base of more than 4,500 systems through a global sales and support network.

Additional information about the company is available on GaSonics' website, located at http://www.gasonics.com

Note to Editors: Integrated Clean(TM) and the Performance Enhancement Platform (PEP) Iridia DL(TM) are licensed trademarks of GaSonics International. All other trademarks mentioned herein are the property of their respective owners. GaSonics cannot guarantee the accuracy of the contents of this document and disclaims liability for any errors, omissions or future changes.