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:
Aug. 03, 1982
Filed:
Jan. 23, 1979
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
356237 ; 356239 ; 356369 ;
Abstract
This invention discloses inspection apparatus for detecting unfavorable foreign matters existent on the surface of an object such as semiconductor wafer. The apparatus includes a collimated beam generator portion which projects a collimated beam towards the object to-be-inspected from a side thereof, and a mechanism which senses light reflected from the surface of the object, through a polarizer plate. In accordance with this invention, the signal-to-noise ratio between a detection signal generated by a pattern of the foreign matter to-be-detected and a signal generated by a normal pattern of the object surface and sensed as a noise component can be enhanced.