CCMP CMC Materials Inc

Cabot Microelectronics Corporation (Nasdaq:CCMP), the world's leading supplier of chemical mechanical planarization (CMP) polishing slurries and growing CMP pad supplier to the semiconductor industry, announced today that it has been recognized as one of 17 suppliers to receive United Microelectronics Corporation's (UMC) Outstanding Supplier award for its performance in 2009. Cabot Microelectronics Corporation was recognized for its significant contributions, providing UMC with CMP slurries deemed essential to UMC's success.

"We are pleased to receive this prestigious supplier award from UMC, a company we value as one of our strategic customers. It reflects our vision statement to be the trusted industry partner, providing high quality solutions with speed, and delivering superior cost of ownership," stated William Noglows, Chairman and CEO of Cabot Microelectronics.

"Cabot Microelectronics Corporation consistently delivers materials that support UMC's demanding technical requirements on advanced technology node CMP process development. Their distinguished service and reliable performance combined with innovative CMP slurry products led to this Outstanding Supplier award. We look forward to continued partnership and success in 2010," said Louis Hsieh, Director, Operation Support Division, UMC.

Celebrations to honor UMC's Outstanding Suppliers were held on May 20, 2010 in conjunction with UMC's 30th anniversary and the launch ceremony for Phase 3 and 4 of Fab12A, located in the Southern Taiwan Science Park.  

ABOUT CABOT MICROELECTRONICS CORPORATION

Cabot Microelectronics Corporation, headquartered in Aurora, Illinois, is the world's leading supplier of CMP polishing slurries and growing CMP pad supplier to the semiconductor industry. The company's products play a critical role in the production of advanced semiconductor devices, enabling the manufacture of smaller, faster and more complex devices by its customers. The company's mission is to create value by developing reliable and innovative solutions, through close customer collaboration, that solve today's challenges and help enable tomorrow's technology. Since becoming an independent public company in 2000, the company has grown to approximately 900 employees on a global basis. For more information about Cabot Microelectronics Corporation, visit www.cabotcmp.com or contact Amy Ford, Director of Investor Relations at (630) 499-2600.

The Cabot Microelectronics Corporation logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=6902

SAFE HARBOR STATEMENT

This news release may include statements that constitute "forward looking statements" within the meaning of federal securities regulations. These forward-looking statements include statements related to: future sales and operating results; company and industry growth, contraction or trends; growth or contraction of the markets in which the company participates; international events or various economic factors; product performance; the generation, protection and acquisition of intellectual property, and litigation related to such intellectual property; new product introductions; development of new products, technologies and markets; the acquisition of or investment in other entities; uses and investment of the company's cash balance; and the construction of facilities by Cabot Microelectronics Corporation. These forward-looking statements involve a number of risks, uncertainties, and other factors, including those described from time to time in Cabot Microelectronics' filings with the Securities and Exchange Commission (SEC), that could cause actual results to differ materially from those described by these forward-looking statements. In particular, see "Risk Factors" in the company's quarterly report on Form 10-Q for the quarter ended March 31, 2010 and in the company's annual report on Form 10-K for the fiscal year ended September 30, 2009, both filed with the SEC. Cabot Microelectronics assumes no obligation to update this forward-looking information.

CONTACT:  Cabot Microelectronics Corporation
          (630) 499-2600