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:
Dec. 15, 2009
Filed:
Jul. 18, 2006
Yoshihiko Sumimoto, Osaka, JP;
Kiyoto Ohta, Osaka, JP;
Yoshihiko Sumimoto, Osaka, JP;
Kiyoto Ohta, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
By simplifying the shape of memory cell diffused mask patterns, the patterns are formed stably and the yield of a semiconductor memory device is improved. Adjacent 2-bit memory cell transistors are formed with one diffused mask pattern, the diffused mask patterns are arranged on a memory cell array, and metal lines are used as source common lines for the memory cells formed at the diffused mask patterns. In this way, that is, by using 2-bit rectangular diffused mask patterns as the memory cell diffused mask patterns and using the metal lines as the source common lines instead of diffused layers, the shape of the memory cell diffused mask patterns is simplified. And furthermore, the continuity of the memory cell diffused mask patterns used as actual memory cells is kept, accuracy in forming the actual memory cell diffused mask patterns is improved, and the yield of the semiconductor memory device is improved.