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:
Jul. 16, 1991
Filed:
Jul. 23, 1990
Applicant:
Inventor:
Yasukazu Seki, Kanagawa, JP;
Assignee:
Fuji Electric Co., Ltd., Kanagawa, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 37 ; 357 231 ; 357 234 ; 357 55 ; 357 59 ;
Abstract
A conductivity modulation MOSFET with two base layers formed over a drain layer. A trench with a lower portion and an upper portion is formed in the second base layer. The lower portion of the trench has a fixed width, and the upper portion of the trench has a steadily increasing width relative to the lower portion. A gate is placed in the lower portion of the trench, while the source regions are formed in the second base region alongside the side walls of the upper trench portion.