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. 18, 1997
Filed:
Dec. 20, 1994
Applicant:
Inventor:
Noriaki Kodama, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
257314 ; 257315 ; 257316 ; 257336 ; 257344 ; 257408 ;
Abstract
There is provided an involatile semiconductor memory deice comprising a virtual ground memory cell array which allows the read current to be increased without degrading the writing characteristic. A source/drain of a memory cell having a floating gate 3 is composed of a double diffusion layer comprising an n.sup.- -type diffusion layer 7 and an n.sup.+ -type diffusion layer 8, the n.sup.+ -type diffusion layer 8 overlaps with one end of the floating gate 3 and the other is provided with an offset of the n.sup.- -type diffusion layer 7.