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:
Jun. 16, 2015
Filed:
Dec. 27, 2010
Kenichi Ohtsuka, Tokyo, JP;
Kenichi Kuroda, Tokyo, JP;
Hiroshi Watanabe, Tokyo, JP;
Naoki Yutani, Tokyo, JP;
Hiroaki Sumitani, Tokyo, JP;
Kenichi Ohtsuka, Tokyo, JP;
Kenichi Kuroda, Tokyo, JP;
Hiroshi Watanabe, Tokyo, JP;
Naoki Yutani, Tokyo, JP;
Hiroaki Sumitani, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A silicon carbide semiconductor element, including: i) an n-type silicon carbide substrate doped with a dopant, such as nitrogen, at a concentration C, wherein the substrate has a lattice constant that decreases with doping; ii) an n-type silicon carbide epitaxially-grown layer doped with the dopant, but at a smaller concentration than the substrate; and iii) an n-type buffer layer doped with the dopant, and arranged between the substrate and the epitaxially-grown layer, wherein the buffer layer has a multilayer structure in which two or more layers having the same thickness are laminated, and is configured such that, based on a number of layers (N) in the multilayer structure, a doping concentration of a K-th layer from a silicon carbide epitaxially-grown layer side is C·K/(N+1).