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:
Feb. 12, 1997
Akihiro Nakae, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
According to a method of correcting light proximity effect, a decision distance from one exposure point to the other exposure point, where influence of the light proximity effect appears, as well as a reference area ratio for deciding as to whether the light proximity effect correction is necessary or not are determined based on an optical condition of an exposure apparatus having a photomask attached thereto. Respective sides of a photomask pattern are divided into portions each having at most a prescribed length, and a ratio of an area occupied by the photomask pattern to an area of a circle having a middle point of each divided side as a center and the decision distance as a radius is determined for each of the divided sides. Comparing the area ratio for each of the divided sides with the reference area ratio for decision, a decision is made for each divided side as to whether the light proximity effect correction is necessary or not. Using this method, time required for calculation can be reduced, and highly precise correction can be made.