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. 26, 2015
Filed:
Mar. 24, 2009
Shun-ichi Nakamura, Matsumoto, JP;
Yoshiyuki Yonezawa, Matsumoto, JP;
Masahide Gotoh, Matsumoto, JP;
Shun-ichi Nakamura, Matsumoto, JP;
Yoshiyuki Yonezawa, Matsumoto, JP;
Masahide Gotoh, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., , JP;
Abstract
A silicon carbide MOS semiconductor device is disclosed which suppresses degradation of efficiency percentage yield with respect to a breakdown voltage even when a surface region with a high impurity concentration is formed by ion implantation with such a high dose as required for attaining a good ohmic contact. The device has a silicon carbide semiconductor substrate, a voltage blocking layer of a first conductivity type formed on the substrate, a body region of a second conductivity type formed on the voltage blocking layer, a body contact region of the second conductivity type formed in a surface region of the body region by selective ion implantation, a surface of the body contact region having such a high impurity concentration as to impart an ohmic contact, a source contact region of the first conductivity type formed in a surface region of the body region by selective ion implantation, a surface of the source contact region having such a high impurity concentration as to impart an ohmic contact, and a source extension region with an impurity concentration lower than that in the source contact region under the source contact region at a region deeper than a tail part of a bottom region of the source contact region by selective ion implantation, the source extension region having an impurity concentration less than 3×10cm.