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:
Dec. 23, 2014
Filed:
Jul. 14, 2011
Kenichi Ohtsuka, Tokyo, JP;
Nobuyuki Tomita, Tokyo, JP;
Tomoaki Furusho, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A semiconductor device that can suppress deterioration in crystal quality caused by a lattice mismatch between a substrate and an epitaxial layer and that also can ensure a voltage sustaining performance, and a wafer for forming the semiconductor device. An epitaxial wafer of silicon carbide (SiC), which is used for manufacturing a semiconductor device, includes a low resistance substrate and an epitaxial layer provided thereon. The epitaxial layer is doped with the same dopant as a dopant doped into the substrate, and has a laminated structure including a low concentration layer and an ultrathin high concentration layer. A doping concentration in the low concentration layer is lower than that in the silicon carbide substrate. A doping concentration in the ultrathin high concentration layer is equal to that in the silicon carbide substrate.