Semitool Penetrates New Porous Silicon Customer Within Solar Industry

KALISPELL, MT--(Marketwire - October 9, 2007) - Semitool, Inc. (NASDAQ: SMTL), a leading manufacturer of wafer processing equipment for the semiconductor industry, today announced it has sold an advanced Raider tool for use in porous silicon formation to a customer focused on development of high-efficiency, low cost-per-watt solar devices.

"Porous Silicon is utilized as an enabling material by a wide range of device makers involved with CMOS, MEMS, sensor and photovoltaic technology," said Kevin Witt, Semitool's director of disruptive technology. "After years of R&D by university research teams, Semitool has now developed and commercialized real-world applications for porous silicon. The use of this material in solar cell production can reduce substrate cost significantly without compromising efficiency or complicating the manufacturing process."

Semitool's porous silicon tools are built on the successful Raider platform. Porous Silicon chambers can be placed on the Raider alone, or in combination with other chambers and processes to form flexible and productive cluster tools.

About Semitool, Inc.

Semitool is a worldwide leader in the design, development, manufacture, and support of highly engineered, single-wafer and multi-wafer batch wet chemical processing systems for use in the fabrication of semiconductor devices. The company's primary suites of equipment include electrochemical deposition systems for electroplating copper, gold, solder and other metals; surface preparation systems for cleaning, stripping and etching silicon wafers; and wafer transport container cleaning systems. The company's equipment is used in semiconductor fabrication front-end and back-end processes, including wafer level packaging.

Headquartered in Kalispell, Montana, Semitool maintains sales and support centers in the United States, Europe and Asia. The company's stock trades on the NASDAQ National Market under the symbol SMTL. For more information, please visit the company's website at www.semitool.com.

Safe Harbor Statement

This news release contains statements related to the Company selling porous silicon equipment into the solar market. The penetration of the solar industry with porous silicon equipment, and our business in general, are subject to risks that can cause actual results to differ materially from those anticipated in our forward-looking statements, including, without limitation, the porous silicon equipment meeting the needs of the customers in the solar industry, demand being adversely affected by the cyclicality in the semiconductor industry, the financial condition of our customers, the company's ability to timely deliver and support its products, technological changes that affect our ability to compete, the risks associated with competing on a global basis as well as a number of other risk factors described in our Annual Report on Form 10-K for the fiscal year ended September 30, 2007 and subsequent filings. We assume no obligation to update forward-looking statements that become untrue because of subsequent events.

Semitool and RAIDER are registered trademarks of Semitool, Inc.

Contact Information: Contacts: Semitool, Inc. Kevin Witt Director of Disruptive technology 406.752.2107 Pfeiffer High Investor Relations, Inc. Geoff High 303.393.7044