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:
Jul. 30, 1996
Filed:
Dec. 28, 1994
Kazuko Oi, Tokyo, JP;
Kiyomi Koyama, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Method and apparatus for designing the photomask in the course of designing the Levenson-type phase shift mask, capable of automatically arranging the shifter, of not causing a contradictory spot in a circuit designing stage and of automatically forming a final layout achieving maximum integrity. The method includes the steps of: forming symbolic layout data in which a distance between adjacent clear areas is set to an arbitrary value; determining regions having a mutual phase difference 0.degree. or 180.degree. of light transmitting through adjacent patterns corresponding to the clear areas in the symbolic layout data; executing compaction of the symbolic layout in a manner that design rule S1 is adopted to the clear areas neighboring with the phase difference of 180.degree. and design rule S2 is adopted to the clear areas neighboring with the phase difference of 0.degree.; and forming mask layout data such that S1 is less than S2.