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:
Jan. 17, 1989
Filed:
Feb. 18, 1987
Koichi Matsumoto, Tokyo, JP;
Yutaka Suenaga, Kawasaki, JP;
Makoto Uehara, Tokyo, JP;
Kiyoyuki Muramatsu, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A projection exposure apparatus has a pattern lighting optical system including an exposure light source for lighting a pattern on a photomask, a projection optical system for forming an image of the pattern lighted by the exposure light source on the surface of a wafer, an alignment lighting optical system including an alignment light source for lighting alignment marks on the photomask and the wafer, and an alignment optical system for detecting relative positional relationship between the mask pattern and the wafer through the projection optical system, and further the projection optical system includes an image-forming system which exhibits two extremums of axial aberration as a function of wavelength.