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:
Oct. 14, 1997
Filed:
Nov. 18, 1994
Applicant:
Inventor:
Hiroshi Nozue, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
355 53 ; 355 71 ;
Abstract
An apparatus for exposing a semiconductor wafer to light, includes a light source, a glass substrate, a mask having thereon a first pattern composed of light-impermeable material, a projection lens, and an illumination optical system for radiating light derived from the light source to said mask to thereby transfer the pattern on a semiconductor wafer. The glass substrate constitutes a part of the illumination optical system and has a plurality of second patterns which are light-permeable and each of which has a different dimension from each other. The second patterns preferably are square in shape, and also preferably a combination of squares and equilateral triangles in shape.