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. 24, 1993
Filed:
Aug. 17, 1990
Applicant:
Inventors:
Yuji Ohkura, Itami, JP;
Masatoshi Fujiwara, Itami, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03C / ; G02B / ;
U.S. Cl.
CPC ...
430321 ; 430323 ; 430329 ; 430396 ; 359566 ; 359569 ; 359577 ;
Abstract
A method for manufacturing a diffraction grating includes applying a resist, the developing speed of which has an extreme at a certain exposure intensity, to a substrate on which the diffraction grating is to be formed, performing interference exposure of the resist with maximum and minimum values of exposure intensity respectively larger and smaller than the intensity which makes the developing speed an extreme, developing the resist, and etching the substrate using the remaining resist as a mask.