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:
Mar. 02, 1993
Filed:
Nov. 07, 1991
Koji Shirai, Kawasaki, JP;
Ken Kawamura, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A semiconductor device comprises a semiconductor substrate of a first conductivity type, a first well of a second conductivity type formed on the semiconductor substrate of the first conductivity type, a first impurity diffusion layer of the first conductivity type formed on the well without contacting the semiconductor substrate, a second impurity diffusion layer of the second conductivity type which surrounds the first impurity diffusion layer and has an impurity concentration which is higher than that of the first impurity diffusion layer, a third impurity diffusion layer of the first conductivity type formed within the second impurity diffusion layer so as to contact neither the semiconductor substrate nor the first impurity diffusion layer, a source electrode connected to both the second impurity diffusion layer and the third impurity diffusion layer, a gate electrode which is formed between the first impurity diffusion layer and the third impurity diffusion layer and formed on the second impurity diffusion layer so as to interpose an insulation film therebetween, a drain electrode connected to the first impurity diffusion layer, and a wiring layer extracted from the drain electrode outside the semiconductor substrate.