October 12, 2001 — WILMINGTON, MA — QC Optics, Inc. recently announced that in accordance with their terms, its redeemable warrants will expire and not be exercisable after the close of business on October 23, 2001.

Accordingly, the warrants will no longer be publicly traded after October 23, 2001. Prior to the close of business on October 23, 2001, each redeemable warrant may be exercised to purchase one share of common stock at a price of $ 7.80. However, as previously announced, we have entered into a definitive merger agreement with KLA-Tencor. Under the terms of the agreement, KLA-Tencor will pay $ 1.00 per share in cash for the issued and outstanding shares of common stock of QC Optics. The transaction is currently expected to close in November. The transaction is subject to the approval of the stockholders of QC Optics and other customary closing conditions. QC Optics has filed a preliminary proxy statement with the U.S. Securities and Exchange Commission. QC Optics expects to mail a proxy statement to its stockholders containing information about the merger. Investors and security holders are urged to read the proxy statement carefully when it is available.

Further information concerning the warrants may be obtained by contacting the warrantholder’s broker, QC Optics or Computershare Investor Services.

QC Optics, Inc. designs, manufactures and markets laser-based defect detection systems for the semiconductor and computer hard disk markets. The company’s systems combine automatic handling, cleanroom capability and computer control with reliable laser-based technology to provide inspection capabilities with the goal of producing increased yields for its customers. Currently, QC Optics has over 350 systems installed in 17 countries.