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:
Dec. 15, 1992
Filed:
Apr. 04, 1991
Applicant:
Inventor:
Noriyuki Mitome, Kawasaki, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356401 ; 250548 ; 355 53 ;
Abstract
An exposure apparatus includes a stage for carrying thereon a wafer; an exposure system for projecting radiation energy to the wafer to print a pattern thereon; and a detection optical system having a sigma value defined as the ratio of the diameter of an image of an aperture of a stop to the diameter of the aperture of the stop for projecting a radiation beam to the wafer and for receiving a reflection beam reflected from the wafer to detect a mark of the wafer which is defined by a level difference on the wafer, the detection optical system including an adjuster for changing the sigma value in accordance with the level difference defining the mark.