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:
Mar. 01, 2005
Filed:
May. 22, 2002
Evgeni Levin, Rehovot, IL;
Gilad Almogy, Givatayim, IL;
Efrat Rozenman, Asseret, IL;
Applied Materials Israel, Ltd., Rehovot, IL;
Abstract
A method to extend the process monitoring capabilities of a semiconductor wafer optical inspection system so as to be able to detect low-resolution effects of process variations over the surface of a wafer at much higher sensitivity than heretofore possible. The method consists, in essence, of grouping sensed pixels by geometric blocks over the inspected surface and comparing each block with a corresponding one from another die on the same wafer, from another wafer or from a stored model image. In one embodiment of the invention, pixel values are compared directly and differences are thresholded at a considerably lower level than during a defects detection process. In another embodiment, there is calculated a signature for each block, based on the sensed light intensity values, and corresponding signatures are compared.