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:
Apr. 19, 2011
Filed:
Jun. 07, 2007
Wakako Takeuchi, Yokohama, JP;
Hiroshi Akahori, Yokohama, JP;
Atsuhiro Sato, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device having high charge retention characteristics and capable of improving leakage characteristics of a dielectric film disposed between a charge storage layer and a control gate electrode, and manufacturing method thereof is disclosed. According to one aspect, there is provided a semiconductor memory device comprising a first electrode disposed on a first insulator on a semiconductor substrate, a second insulator disposed on the first electrode, a second electrode disposed on the second insulator, and diffusion layers disposed in the semiconductor substrate, wherein the second insulator including a silicon-rich silicon nitride film containing more silicon than that in a stoichiometric silicon nitride film, and a silicon oxide film formed on the silicon-rich silicon nitride film, and wherein the silicon-rich silicon nitride film has a ratio of a silicon concentration and a nitrogen concentration set to 1:0.9 to 1:1.2.