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:
Mar. 09, 2010
Filed:
Dec. 27, 2005
Hiroyuki Nansei, Aizuwakamatsu, JP;
Hiroyuki Nansei, Aizuwakamatsu, JP;
Spansion LLC, Sunnyvale, CA (US);
Abstract
A semiconductor memory device, firstly, has both the thickness of a tunnel film and that of a top film provided thereon and configured to be in the FN tunneling region (4 nm or more). The data retention characteristics can be improved by configuring both the thickness of a tunnel film and that of a top film to have a thickness of in the FN tunneling region. Secondly, a high-concentration impurity region of a conductivity type the same as that of the substrate is provided in a substrate region arranged between assist gates provided adjacently to each other. The aforementioned high-concentration impurity region makes a depletion layer extremely thin when bias is applied to the assist gates. Hot holes generated between bands in the depletion region are injected into a charge storage region and the holes and electrons make pairs and disappear, enabling easy data erasing.