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:
Jul. 06, 2004
Filed:
Jul. 17, 2003
Shu Shimizu, Tokyo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device including a semiconductor substrate , a plurality of memory cells on the semiconductor substrate including transistors having floating gate electrodes and control gate electrodes. Source lines are formed in a self-alignment manner with respect to a control gate electrodes. The surface of the semiconductor substrate has such a periodical unevenness along the source lines which has a diffusion layer that an impurity is distributed along the surface of the semiconductor substrate and a buried diffusion layer that an impurity is distributed at a position deeper than said diffusion layer . The buried diffusion layer connects a plurality of portions of the diffusion layers under the bottom surface of the recess portion to each other.