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:
Apr. 28, 1987
Filed:
Oct. 29, 1985
Yoshihisa Mizutani, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An electrically erasable and programmable read only memory comprises a semiconductor substrate of a first conductivity type, source and drain regions both of a second conductivity type formed in the surface of said semiconductor substrate, a gate insulation film formed on that section of the surface of said substrate which includes a channel region defined between said source and drain regions, a first diffusion region of the second conductivity type, part of which is formed in said substrate and contacts said drain region and which has a lower impurity concentration than said drain region, a first insulation film formed on said first diffusion region, a floating gate formed on said gate insulation film, part of which extends over said first insulation film, a second diffusion region of the first conductivity type formed in the surface of said first diffusion region which lies near said extension of the floating gate, a third diffusion region of the first conductivity type formed in the surface of said first diffusion region, a second insulation film covering said floating gate, and a control gate crossing at least that section of the surface of said second insulation layer which faces part of said floating gate.