ON Semiconductor Corporation Completes Merger of AMIS Holdings, Inc.

ON Semiconductor Corporation (NASDAQ: ONNN) announced that it has completed its acquisition of AMIS Holdings, Inc. (NASDAQ: AMIS) in a stock-for-stock merger. Under the terms of the merger agreement, holders of AMIS will generally receive 1.15 shares of ON Semiconductor common stock for each share of AMIS common stock they own as of the close of business today. ON Semiconductor will issue a total of approximately 103 million shares of common stock on a fully diluted basis to complete the transaction. Former AMIS stockholders now own approximately 26 percent of ON Semiconductor. At closing, ON Semiconductor repaid AMISs senior bank facility with cash on hand from both companies.

“The merger represents an important step in the transformation of ON Semiconductor,” said Keith Jackson, ON Semiconductor president and chief executive officer. “ON Semiconductor is now solidly positioned as a global leader of efficient power and analog solutions. The acquisition brings together ON Semiconductors leading standard products, operational excellence and manufacturing infrastructure with AMISs substantial custom product portfolio enabling us to more comprehensively address our customers needs. Furthermore, we expect to achieve significant operating and manufacturing cost savings. Starting this week, the company will begin executing the planned operational integration of the two companies to ensure a smooth transition and create immediate value for our customers, partners and investors.”

“Our merger with ON Semiconductor is a great opportunity for our customers, employees, stockholders and their future,” said Christine King, AMISs former chief executive officer and president. “I am also looking forward to joining the ON Semiconductor board of directors effective today.”

Additional details regarding the acquisition will be made available during a conference call to discuss ON Semiconductors first quarter 2008 results. The call is currently scheduled for May 7, 2008. During this call, the company also intends to discuss the gross margin and net income per share effects associated with the purchase accounting rules. Specifically, the company will outline the amortization of intangibles, in-process research and development charges, write-up of inventories and other non-cash transaction-related impacts to our financial statements. These purchase accounting rules should have no impact to the ongoing free cash flow of ON Semiconductor but will affect U.S. GAAP gross margins and net income per share for a period of time.

About ON Semiconductor

With its global logistics network and strong product portfolio, ON Semiconductor (NASDAQ: ONNN) is a preferred supplier of efficient power solutions to customers in the power supply, automotive, communication, computer, consumer, medical, industrial, mobile phone, and military/aerospace markets. The companys broad portfolio includes power, analog, DSP, mixed-signal, advance logic, clock management and standard component devices. Global corporate headquarters are located in Phoenix, Arizona. The company operates a network of manufacturing facilities, sales offices and design centers in key markets throughout North America, Europe, and the Asia Pacific regions. For more information, visit www.onsemi.com.