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:
Sep. 26, 1989
Filed:
Jul. 01, 1988
Applicant:
Inventors:
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 43 ; 356400 ; 356349 ;
Abstract
A projection exposure apparatus is provided with an optical member, capable of transmitting the exposure light of a first wavelength, placed between a projection optical system and a wafer. The alignment light of a second wavelength for pattern detection is introduced obliquely to the wafer surface through the optical member. A pattern in the projection exposure area or in the vicinity thereof, particularly an alignment mark can be detected by means of the reflection and transmission characteristics.