The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 20, 1998
Filed:
Jan. 27, 1997
Akram Aref Bou-Ghannam, Boca Raton, FL (US);
Alan David Dorundo, Boca Raton, FL (US);
Michael Gerard Lisanke, Boynton Beach, FL (US);
Huizong Lu, Coconut Creek, FL (US);
Lanphuong Thi Pena, Ft. Lauderdale, FL (US);
Ali Reza Taheri, West Palm Beach, FL (US);
Samuel Sheung-Lok So, San Jose, CA (US);
Kenneth Wayne Watts, Boca Raton, FL (US);
Darell Smith Whitaker, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An interferometer is used to locate and examine defects in a test surface of a test specimen. Defects are first located as the test surface is driven past the objective of the interferometer at a constant speed, with a darkfield interferogram being examined as it flows across a row of CCD elements. During this process, the location of each defect is stored. Next, the test specimen is sequentially moved into the locations at which static measurements are made using an area array of CCD elements. During these measurements, the phase angle relationship of the interferometer is varied so that heights of surface segments may be calculated. If some to these segments are located more than a quarter wave length of the interferometer light source from the surface at which the darkfield is established, a process is used to perform height corrections for segments within transition boundaries.