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:
Oct. 20, 1998
Filed:
Apr. 09, 1997
Mehrdad Nikoonahad, Atherton, CA (US);
Charles E Wayman, San Jose, CA (US);
Kla-Tencor Corporation, San Jose, CA (US);
Abstract
An optical surface inspection system is designed to correct for misregistration errors. A reference vector of data samples is obtained by computing an average of adjacent data sample vectors. A comparison of the data samples in a current vector being processed to data samples that may be offset from such current vector along the direction of the current vector enables the detection and correction of misregistration errors. Alternatively, a target array of data samples is compared to a reference array of data samples collected from a different portion of the surface with various offsets for detection and correction of misregistration errors. The intensity of the reflection from the inspection beam may be monitored to vary the intensity of the inspection beam so as to reduce the dynamic range of background scattering.