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. 07, 1992
Filed:
Jun. 17, 1991
Applicant:
Inventor:
Bradley W Scheer, Sunnyvale, CA (US);
Assignee:
VLSI Standards, Inc., Mountain View, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
356243 ;
Abstract
A patterned wafer for testing an optical scanner. The wafer has standard size light scattering features, such as pits, distributed in aligned groups arranged in annular bands about a concentric center. Empty annular bands separate the feature containing annular bands. The empty bands simulate wafer edges for various size wafers. In this manner, wafer edges may be excluded in a particle count for a predetermined size wafer. Apparent size variations in multiple scans indicate misalignments relative to the scan center.