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:
Jan. 20, 2009
Filed:
Mar. 14, 2008
Seiichi Mori, Tokyo-To, JP;
Seiichi Mori, Tokyo-To, JP;
Kabushiki Kaisha Toshiba, Kanagawa-Ken, JP;
Abstract
A non-volatile semiconductor memory device according to the present invention has a semiconductor substrate and a memory cell having a floating gate provided through a tunnel insulating layer on the semiconductor substrate, and a control gate provided through an inter-layer insulting layer on said floating gate. The inter-insulating layer includes a silicon oxide layer contiguous to said floating gate, a first silicon nitride layer provided by a CVD method on the silicon oxide layer and a second silicon nitride layer provided on said first silicon nitride layer and having a lower trap density than that of the first silicon nitride layer. The inter-insulating layer may includes a silicon oxide layer contiguous to said floating gate and a silicon oxide layer deposited on said silicon oxide layer and having a quantity of hydrogen content on the order of 10/cmor less. The inter-insulating layer also may includes a silicon oxide layer serving as a layer contiguous to at least one of the floating gate and the control gate, and having a lower trap density than that of a silicon nitride layer formed by a CVD method.