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:
Feb. 24, 2015
Filed:
Feb. 24, 2014
Renesas Electronics Corporation, Kawasaki, JP;
Tohru Kawai, Kawasaki, JP;
Takashi Inoue, Kawasaki, JP;
Tatsuo Nakayama, Kawasaki, JP;
Yasuhiro Okamoto, Kawasaki, JP;
Hironobu Miyamoto, Kawasaki, JP;
Renesas Electronics Corporation, Kawasaki-Shi, Kanagawa, JP;
Abstract
A semiconductor device includes a buffer layer, a channel layer and a barrier layer formed over a substrate, a trench penetrating through the barrier layer to reach the middle of the channel layer, and a gate electrode disposed inside the trench via a gate insulating film. The channel layer contains n-type impurities, and a region of the channel layer positioned on a buffer layer side has an n-type impurity concentration larger than a region of the channel layer positioned on a barrier layer side, and the buffer layer is made of nitride semiconductor having a band gap wider than that of the channel layer. The channel layer is made of GaN and the buffer layer is made of AlGaN. The channel layer has a channel lower layer containing n-type impurities at an intermediate concentration and a main channel layer formed thereon and containing n-type impurities at a low concentration.