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:
Jan. 14, 1997
Filed:
Oct. 26, 1990
Toshiro Tsumori, Kanagawa, JP;
Hideo Shimizu, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An exposure mask having phase shifting films of a predetermined thickness composed of a material transparent to the wavelength of exposure light and formed on a substrate transparent to such wavelength for causing a desired phase shift, wherein the phase shifting films are so patterned as to principally have arrangement of repeated patterns. Relative to the rule width L of the repeated patterns projected onto a work member to be exposed, a pattern having a rule width of 2 L/m is formed, in which m (.ltoreq.1) is a size reduction magnification in the use of a reduced-size projection exposer. The exposure mask is adapted for use in producing a diffraction grating as well. The mask is easily manufacturable without the necessity of any intricate process such as a positioned exposure, hence minimizing the number of required steps in manufacture while achieving a further fine work with an enhanced resolution higher than the known value.