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:
Dec. 21, 1993
Filed:
Aug. 21, 1992
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G21K / ;
U.S. Cl.
CPC ...
378 35 ; 378 85 ; 430-5 ;
Abstract
In a reflection mask, there is formed at least one laminate structure comprising a high reflectivity portion, a middle portion and a high reflectivity portion. When there is a defect in the high reflectivity portion as the top layer, this high reflectivity portion and the underlying middle portion are removed in that defective position, thereby allowing the high reflectivity portion as the bottom layer to be exposed to repair the defect.