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:
Nov. 16, 1993
Filed:
Feb. 10, 1993
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor device comprises a semiconductor substrate, a semiconductor layer of a first conductivity type formed on said semiconductor substrate, a first semiconductor well region of a second conductivity type and second semiconductor well regions of the second conductivity type, the latter two types of regions being formed in said semiconductor layer. The first semiconductor well region is located at the peripheral area of the semiconductor, and the well is deeper than the well of the second semiconductor well regions. Third semiconductor well regions of the first conductivity type are formed in the second semiconductor well regions. Gate electrodes and an emitter (source) electrode are formed at specified positions on the upper surface of the semiconductor device, and a collector (drain) electrode is formed on the bottom surface.