MENLO PARK, CA, JULY 27, 2006 — Ultra Clean Holdings, Inc. (NASDAQ: UCTT), the parent company of Ultra Clean Technology Sales and Service, a leading developer and supplier of critical subsystems for the semiconductor capital equipment industry, today announced a strategic supplier partnership with Mattson Technology, Inc. (NASDAQ: MTSN), a leading supplier of advanced process equipment used to manufacture semiconductors. Under the terms of the partnership, Ultra Clean integrates and tests critical subsystems on Mattson’s advanced strip and rapid thermal processing (RTP) tools.

"Our flexible business model initiative requires strategic partnerships within our supply chain to lower manufacturing and design costs while improving delivery times to our customers," said Frank R. Kohoutek, Vice President of Operations for Mattson Technology. "This collaboration is another example of how our cyclically flexible enterprise partnerships enable us to enhance business agility and reduce the time-to-market of our high-productivity, technologically advanced Strip and RTP systems."

Clarence Granger, Chief Executive Officer of Ultra Clean Holdings, remarked, "Mattson Technology selected Ultra Clean for our manufacturing expertise and dedicated customer support; we are excited that Mattson has chosen to partner with us. We look forward to leveraging our resources and capabilities to help our valued customer maximize productivity and cost efficiencies to meet the industry demand for its enabling technologies."

About Ultra Clean Holdings, Inc.
Ultra Clean Holdings, Inc. is a developer and supplier of critical subsystems for the semiconductor capital equipment industry. Ultra Clean offers its customers a complete outsourced solution for liquid and gas delivery systems, catalytic steam generation systems and a growing list of critical subsystems. The company can facilitate improved design-to-delivery cycle times and offers component neutral design and manufacturing and component testing capabilities. Ultra Clean’s customers are primarily original equipment manufacturers of semiconductor capital equipment. The company is headquartered in Menlo Park, California. Additional information is available at www.uct.com.

About Mattson Technology, Inc.
Mattson Technology, Inc. is the leading supplier of dry strip equipment and the second largest supplier of rapid thermal processing equipment in the global semiconductor industry. The company’s strip and RTP equipment utilize innovative technology to deliver advanced processing performance and productivity gains to semiconductor manufacturers worldwide for the fabrication of current- and next-generation devices. 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.

Media contact:

Ultra Clean Technology
Mr. Kamal Bhatia
150 Independence Drive, Menlo Park, CA 94025
(650) 323-4100 – fax (650) 326-0929
kbhatia@uct.com

Robert Goldberg & Associates
Mr. Robert Goldberg
6700 Liggett Drive, Oakland, CA 94611
(510) 238-0800
robert@adfarm.com

Mattson Technology
Tanja Froehlingsdorf
47131 Bayside Parkway
Fremont, CA 94538
(510) 492-6342 – fax (510) 492-2800
Tanja.Froehlingsdorf@mattson.com