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:
May. 12, 1987
Filed:
Dec. 16, 1983
Applicant:
Inventor:
Yoshihisa Mizutani, Tokyo, JP;
Assignee:
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; G11C / ;
U.S. Cl.
CPC ...
357 235 ; 365185 ;
Abstract
A semiconductor memory device includes n.sup.+ -type first and second semiconductor regions which are separately formed in the surface area of a p-type semiconductor substrate, a floating gate and a control gate. The second semiconductor region acting as a drain in a data readout mode is composed of a main portion, and an additional portion having an impurity concentration lower than that of the main portion and formed in contact with the main portion and a channel region.