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:
Aug. 30, 2011
Filed:
Jul. 17, 2008
Mitsuhiro Noguchi, Yokohama, JP;
Minori Kajimoto, Yokkaichi, JP;
Mitsuhiro Noguchi, Yokohama, JP;
Minori Kajimoto, Yokkaichi, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device includes a first well of a first conductivity type, which is formed in a semiconductor substrate of the first conductivity type, a plurality of memory cell transistors that are formed in the first well, a second well of a second conductivity type, which includes a first part that surrounds a side region of the first well and a second part that surrounds a lower region of the first well, and electrically isolates the first well from the semiconductor substrate, and a third well of the second conductivity type, which is formed in the semiconductor substrate. The third well has a less depth than the second part of the second well.