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:
Aug. 13, 1991
Filed:
Mar. 16, 1990
Makoto Yoshizawa, Tokyo, JP;
Katsuaki Mohri, Yokohama, JP;
Takeshi Nakashiro, Yokohama, JP;
Tadashi Maruyama, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A nonvolatile semiconductor memory is a programmable and erasable nonvolatile semiconductor memory including a semiconductor substrate of a first conductivity type, source and drain diffusion layers in the semiconductor substrate, and a channel region between the source and drain diffusion layers. A first insulation film is continuously on the channel region and the drain diffusion layer adjacent to the channel region, and a floating gate layer is on the first insulation film. Further, a second insulation film having a thin film portion which is thinner than the first insulation film is on the floating gate layer, and a control gate layer is on the second insulation film.