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:
Sep. 07, 1993
Filed:
Dec. 12, 1991
Ichiro Murai, Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A semiconductor memory device including a semiconductor substrate of a first conduction type, a memory cell having a floating gate and a control gate which are formed on a main surface of the semiconductor substrate and stacked with an interlayer insulating film interposed therebetween and having a three-layer structure of an oxide film, a nitride film and another oxide film, a decoder for supplying a voltage to the memory cell, a first well formed on the substrate surface and having a second conduction type different from the first conduction type, and a second well formed in the first well and having the first conduction type, wherein one of the memory cell and the decoder is formed in the second well.