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. 20, 1993
Filed:
Aug. 05, 1991
Minoru Yoshioka, Shiki, JP;
Mitsuo Matsunami, Tenri, JP;
Toshiaki Miyajima, Ikoma, JP;
Hideyuki Tsuji, Tenri, JP;
Sharp Kabushiki Kaishi, Osaka, JP;
Abstract
vertical power MOSFET which comprises a semiconductive substrate of a first conductivity type serving as drain, an impurity region of a second conductivity type on a part of the surface of the semiconductive substrate, an impurity region of a first conductivity type formed on a part of the surface of the second conductivity type impurity region and serving as source, and a surface portion of a second conductivity type semiconductive substrate between source and drain serving as a channel portion with a gate electrode thereon through an insulating film, so that voltage is applied to the gate electrode to control channel current between source and drain, wherein the first conductivity type semiconductive substrate comprises a low resistivity layer and a high resistivity layer epitaxially formed on the low resistivity layer, and at an interface between the low resistivity layer and the high resistivity layer is provided a convexed portion which projects at least to the high resistivity layer side.