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. 19, 2008
Filed:
Oct. 11, 2007
Hiroshi Akahori, Yokohama, JP;
Wakako Takeuchi, Yokohama, JP;
Yoshio Ozawa, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device includes a first insulating film provided on a surface of a semiconductor substrate, a charge accumulation layer provided on the first insulating film, a second insulating film provided above the charge accumulation layer and contains silicon and nitrogen, a third insulating film provided on the second insulating film, and composed of a single-layer insulating film containing oxygen or a plural-layer stacked insulating film at least whose films on a top layer and a bottom layer contain oxygen, relative dielectric constant thereof being larger than it of a silicon oxide film, a fourth insulating film provided on the third insulating film and contains silicon and nitrogen, a control gate provided above the fourth insulating film, and a fifth insulating film provided between the charge accumulation layer and the second insulating film or between the fourth insulating film and the control gate, and contains silicon and oxygen.