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:
Mar. 09, 2021
Filed:
Mar. 04, 2020
Fuji Electric Co., Ltd., Kanagawa, JP;
Takeyoshi Nishimura, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., Kanagawa, JP;
Abstract
A semiconductor layer may be subjected to etching to form a trench therein. An epitaxial layer may be further formed in the trench. Here, the impurity concentration of the epitaxial layer is controlled to be lower than that of the semiconductor layer. In this manner, concentration of electrical fields in the trench is reduced. A first innovations herein provides a semiconductor device including a first semiconductor layer containing impurities of a first conductivity type, a trench provided in the first semiconductor layer on a front surface side thereof, and a second semiconductor layer provided on an inner wall of the trench, where the second semiconductor layer contains impurities of the first conductivity type at a lower concentration than the first semiconductor layer.