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:
Feb. 18, 1997
Filed:
Dec. 16, 1994
Applicant:
Inventors:
Assignee:
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03F / ;
U.S. Cl.
CPC ...
430-5 ; 430322 ; 430324 ;
Abstract
The invention provides a halftone phase shift photomask that is of much more simplified structure and so can be fabricated much more easily, which comprises a transparent substrate 10 and a single halftone light-blocking and phase shift layer 11 that is formed on the surface thereof according to a predetermined pattern and is made up of a material of homogeneous composition, characterized in that: said single halftone light-blocking and phase shift layer has a film thickness d that is virtually equal to a value defined by