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:
Jun. 02, 1987
Filed:
Nov. 03, 1983
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
356237 ; 250572 ;
Abstract
The foreign particle detecting method and apparatus are disclosed wherein a polarized laser beam emitted by a laser beam irradiating system from a direction inclined with respect to the direction perpendicular to the surface of a substrate is used by a scanning means to linearly scan the substrate surface from a direction approximately 90.degree. with respect to the laser light irradiating direction; and the laser light reflected from a foreign particle on the substrate surface is detected by a polarized light analyzer and a photoelectric conversion device from a direction set approximately equal to said scanning direction and inclined with respect to the direction perpendicular to the substrate surface.