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. 25, 1994
Filed:
Mar. 19, 1992
Satoshi Haraichi, Yokohama, JP;
Fumikazu Itoh, Fujisawa, JP;
Akira Shimase, Yokohama, JP;
Hiroshi Yamaguchi, Fujisawa, JP;
Junzou Azuma, Yokohama, JP;
Yasuhiro Koizumi, Sayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A defect of a phase shift mask, which has a phase shifter disposed on a transparent substrate, formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough and an etching stopper disposed between the phase shifter and the transparent substrate, which is resistant to an etching to which the phase shifter is subjected and transparent for exposure light is corrected by selectively etching a defective portion of the phase shifter, having a lacking type defect, with respect to the etching stopper layer along the whole thickness of the phase shifter and by perforating a portion of the etching stopper layer and the transparent substrate positioned under the etched defective portion by a depth which corresponds to a magnitude of an optical path of the phase shifter for the exposure light, the etching being a reactive etching which uses charged particle beam and a reactive gas and, the bottom surface of a portion etched being flattened by utilizing a fact that the phase shifter is selectively etched.