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. 07, 2020
Filed:
Nov. 28, 2016
Mitsubishi Electric Corporation, Tokyo, JP;
Kenichi Hamano, Tokyo, JP;
Akihito Ohno, Tokyo, JP;
Takuma Mizobe, Tokyo, JP;
Masashi Sakai, Tokyo, JP;
Yasuhiro Kimura, Tokyo, JP;
Yoichiro Mitani, Tokyo, JP;
Takashi Kanazawa, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A semiconductor wafer includes a silicon carbide substrate having a first carrier concentration, a carrier concentration transition layer, and an epitaxial layer provided on the carrier concentration transition layer, the epitaxial layer having a second carrier concentration, and the second carrier concentration being lower than the first carrier concentration. The carrier concentration transition layer has a concentration gradient in the thickness direction. The carrier concentration decreases as the film thickness increases from an interface between a layer directly below the carrier concentration transition layer and the carrier concentration transition layer, and the carrier concentration decreases at a lower rate of decrease as the film thickness of the carrier concentration transition layer increases. The carrier concentration of the carrier concentration transition layer has the concentration gradient that falls within a predetermined concentration range lying between a first concentration gradient condition and a second concentration gradient condition.