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:
Feb. 02, 1999
Filed:
Dec. 02, 1996
Tamae Haruki, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A phase shifter arranging method selectively arranges phase shifters on aperture patterns of a photomask so that a phase difference of .pi.radians occurs between lights transmitted through mutually adjacent aperture patterns of the photomask. The phase shifter arranging method is computer-implemented and comprises the steps of (a) extracting connections of nodes via branch as a net, where each aperture pattern is taken as a node, and mutually adjacent aperture patterns having an interval less than or equal to a predetermined value D0 are taken as nodes connected via a branch, (b) dividing the net into an open net and a closed net which are independent of each other, where the open net has no closed loop and the closed loop is other of the open loop, and (c) selectively arranging the phase shifters with respect to each of mutually independent closed nets.