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. 25, 1992
Filed:
Jun. 02, 1989
Seiichi Iwamatsu, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A trench gate MOS FET having one of the following features: a drain diffusion layer and/or a source diffusion layer having a two-layer structure consisting of a high concentration layer and a low concentration layer; at least a drain diffusion layer having a low concentration layer adjacent to the semiconductor surface of a trench gate and a high concentration layer adjacent to the low concentration layer; a gate oxide film formed to have a greater thickness at the overlapping portion of the diffusion layer and the gate electrode than at the other portions thereof; two trench gates provided on the semiconductor surface so as to control the conductivity of a channel region between the trench gates; or a trench isolation region provided on the semiconductor substrate in contact with the trench gate.