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:
May. 07, 2019
Filed:
Dec. 18, 2017
Fuji Electric Co., Ltd., Kawasaki-shi, Kanagawa, JP;
National Institute of Advanced Industrial Science and Technology, Tokyo, JP;
Naoyuki Ohse, Matsumoto, JP;
Yusuke Kobayashi, Tsukuba, JP;
Takahito Kojima, Matsumoto, JP;
Shinsuke Harada, Tsukuba, JP;
FUJI ELECTRIC CO., LTD., Kawasaki-Shi, Kanagawa, JP;
NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, Tokyo, JP;
Abstract
A vertical MOSFET of a trench gate structure includes an n-type drift layer and a p-type base layer formed by epitaxial growth. The vertical MOSFET includes a trench that penetrates the n-type drift layer and the p-type base layer. A low-concentration thin film is provided in the trench. The low-concentration thin film is in contact with the p-type base layer and is of the same conductivity type as the p-type base layer. Further, the low-concentration thin film has an impurity concentration that is lower than that of the p-type base layer.