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:
Oct. 05, 1999
Filed:
Oct. 03, 1996
Norihisa Arai, Omiya, JP;
Kabushiki Kaisha Tosbhia, Kawasaki, JP;
Abstract
The semiconductor device having a multilayer gate type transistor constituting memory, comprises a P-type semiconductor substrate, a source formed by diffusing an N-type impurity on a surface of the semiconductor substrate to a first depth, an N-type drain, electrically separated from the source and formed on a surface of the semiconductor substrate, a first insulating film formed on a surface of a channel region between the source and the drain, a first gate electrode formed on a surface of the first insulating film, a second insulating film formed on a surface of the first gate electrode, and a second gate electrode on the second insulating film. The semiconductor device further comprises a source wiring region, which is connected to the source of the multilayer gate transistor and formed by diffusing the N-type impurity in the semiconductor substrate to a second depth shallower than the first depth.