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:
Nov. 23, 1999
Filed:
Dec. 15, 1997
Noboru Yokoya, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A mask pattern applied to a peripheral portion of a wafer has an open/close ratio substantially the same as that in a central portion thereof and prepared according to a looser design rule than that for forming the central portion. The looser design rule has a high latitude for out-of-focus exposure and provides high resistance to pattern removal. Since the open/close ratios in the central portion and the peripheral portion of the wafer are substantially the same, variance in process accuracy due to a micro-loading effect can be prevented.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile