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:
Aug. 15, 1995
Filed:
Oct. 05, 1994
Masaichi Murakami, Tokyo, JP;
Muneyasu Yokota, Tokyo, JP;
Toshio Matsuura, Tokyo, JP;
Atsuyuki Aoki, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Prior to exposures, the imaging characteristics of a projection optical system to be used are determined by measuring the positions of plural projection points (evaluation points) within the projection area, on a photosensitive substrate, of the projection optical system. Then the positional aberrations between the evaluation points are determined in the area of image superposition or jointing, and correcting parameters are determined so as to minimize at least the component of the aberrations in a direction, perpendicular to an extending direction patterns of a reticle. The reticle or the photosensitive substrate is rotated or shifted according to thus determined correcting parameters. This exposure method achieves the superposition or jointing of patterns, or the superposition of the jointed parts thereof, in optimum manner, according to the structure (directionality) of the patterns or the imaging characteristics of the projection optical system employed.