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. 27, 2007
Filed:
May. 30, 2006
Daigo Hoshino, Sendai, JP;
Daigo Hoshino, Sendai, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A phase shift mask comprises first and second mask patterns. The first mask pattern is a backing film enabling a first optical image to be formed on a substrate. The first optical image forms a resist pattern having a width that changes depending on the distance between the phase shift mask and the substrate. The second mask pattern is a semi-transmissive film enabling a second optical image to be formed on the substrate. The second optical image can form a resist pattern having a width that changes depending on the distance between the phase shift mask and the substrate and on a thickness of the semi-transmissive film. The duty ratio of the second mask is set so that the rate at which the width of the first optical image varies will be the same as the rate at which the width of the second optical image varies.