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:
Jun. 12, 2012
Filed:
Mar. 24, 2008
Masayuki Tanaka, Yokohama, JP;
Yoshio Ozawa, Yokohama, JP;
Hirokazu Ishida, Yokohama, JP;
Katsuaki Natori, Yokohama, JP;
Seiji Inumiya, Tsukuba, JP;
Masayuki Tanaka, Yokohama, JP;
Yoshio Ozawa, Yokohama, JP;
Hirokazu Ishida, Yokohama, JP;
Katsuaki Natori, Yokohama, JP;
Seiji Inumiya, Tsukuba, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device includes a semiconductor substrate, an isolation insulation film filled in a plurality of trenches formed in the semiconductor substrate to define a plurality of element formation regions, a floating gate of polysilicon provided on each of the element formation regions through a first insulation film, a second insulation film, provided on the floating gate, containing a metal element, a control gate of polysilicon, provided on the second insulation film, and source/drain regions provided in the semiconductor substrate, both a polysilicon conductive layer containing a metal element and a mutual diffusion layer composed of a silicate layer of a mixed oxide material composed of a silicon element contained in the floating gate and the control gate and a metal element contained in the second insulation film are provided on a surface of each of the floating gate and the control gate, respectively.