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:
Jul. 02, 2013
Filed:
Jun. 29, 2010
Ken Komiya, Yokohama, JP;
Ken Komiya, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device comprises: element isolation insulating films formed in a semiconductor substrate in a first direction; and element regions formed in a region sandwiched by the element isolation insulating film, with MONOS type memory cells. The MONOS type memory cell comprises: a tunnel insulating film disposed on the element region; a charge storage film disposed continuously on the element regions and the element isolation insulating films. The charge storage film comprises: a charge film disposed on the element region and having a certain charge trapping characteristic; and a degraded charge film disposed on the element isolation insulating film and having a charge trapping characteristic inferior to that of the charge film. The degraded charge film has a length of an upper surface thereof set shorter than a length of a lower surface thereof in a cross-section along the first direction.