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:
Oct. 27, 1998
Filed:
Oct. 30, 1996
Applicant:
Inventors:
Shinji Ishida, Tokyo, JP;
Tadao Yasuzato, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
430-5 ;
Abstract
In a halftone type phase shift photomask, a patterned halftone layer is formed on a transparent substrate, and a light screen layer is formed on the halftone layer. A part of a mask pattern is changed from opaque to halftone, thus improving the resist pattern fidelity.