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:
Mar. 06, 2007
Filed:
Jun. 08, 2004
Yutaka Hirose, Kyoto, JP;
Daisuke Ueda, Osaka, JP;
Tsuyoshi Tanaka, Osaka, JP;
Yasuhiro Uemoto, Shiga, JP;
Tomohiro Murata, Osaka, JP;
Yutaka Hirose, Kyoto, JP;
Daisuke Ueda, Osaka, JP;
Tsuyoshi Tanaka, Osaka, JP;
Yasuhiro Uemoto, Shiga, JP;
Tomohiro Murata, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor device has a sapphire substrate, a semiconductor layer made of GaN provided on the sapphire substrate, a multilayer film provided on the semiconductor layer, and an electrode in ohmic contact with the multilayer film. The multilayer film has been formed by alternately stacking two types of semiconductor layers having different amounts of piezopolarization or different amounts of spontaneous polarization and each containing an n-type impurity so that electrons are induced at the interface between the two types of semiconductor layers. This allows the contact resistance between the electrode and the multilayer film and a parasitic resistance in a current transmission path to be reduced to values lower than in a conventional semiconductor device.