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:
Apr. 02, 2013
Filed:
Aug. 13, 2010
Makoto Miyoshi, Nagoya, JP;
Yoshitaka Kuraoka, Nagoya, JP;
Shigeaki Sumiya, Nagoya, JP;
Mikiya Ichimura, Nagoya, JP;
Tomohiko Sugiyama, Nagoya, JP;
Mitsuhiro Tanaka, Nagoya, JP;
Makoto Miyoshi, Nagoya, JP;
Yoshitaka Kuraoka, Nagoya, JP;
Shigeaki Sumiya, Nagoya, JP;
Mikiya Ichimura, Nagoya, JP;
Tomohiko Sugiyama, Nagoya, JP;
Mitsuhiro Tanaka, Nagoya, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
Provided is an epitaxial substrate capable of achieving a semiconductor device that has excellent schottky contact characteristics as well as satisfactory device characteristics. On a base substrate, a channel layer formed of a first group III nitride that contains at least Al and Ga and has a composition of InAlGaN (x1+y1+z1=1) is formed. On the channel layer, a barrier layer formed of a second group III nitride that contains at least In and Al and has a composition of InAlGaN (x2+y2+z2=1) is formed such that an In composition ratio of a near-surface portion is smaller than an In composition ratio of a portion other than the near-surface portion.