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:
Mar. 12, 1991
Filed:
Jul. 13, 1988
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
353122 ; 353101 ;
Abstract
A projection apparatus for projecting through an optical system a circuit pattern formed on a mask or reticle onto a wafer. Ambient or environment conditions of the apparatus, such as an atmospheric pressure, temperature and humidity are detected and, on the basis of the results of detection, any focus error and magnification error upon pattern projection on the wafer are corrected.