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. 18, 1998
Filed:
Mar. 27, 1996
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A method for designing a photomask, used in photolithography using partially coherent incident light, the photomask having a substrate on which a plurality of transparent regions and opaque regions are formed, the transparent regions including a phase shifter for providing the incident light transmitting through the transparent regions with a phase difference, the method comprising the steps of extracting combinations of patterns adjacent to each other within a distance of a threshold value S2 as adjacent pairs from patterns corresponding to the transparent regions, calculating difficulty of correction of the adjacent pairs, sorting the adjacent pairs in an descending order of the difficulty of correction, connecting the patterns in the adjacent pairs to one another, such that a pair of adjacent patterns are not connected to each other and loop cut is performed if a closed loop is formed by connecting the adjacent patterns, and a pair of adjacent patterns are logically connected if a closed loop is not formed by connecting the adjacent patterns, and determining phases of light transmitted through the patterns, so that a phase of one of a pair of patterns is opposite to that of the other, on the basis of an inversion relationship finally obtained by the connecting step.