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:
Oct. 14, 2014
Filed:
Feb. 21, 2013
Ngk Insulators, Ltd., Nagoya, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
Provided is a semiconductor device of normally-off operation type having a low on-resistance. An epitaxial substrate for it includes: a base substrate; a channel layer made of a first group-III nitride having a composition of InAlGaN at least containing Al and Ga and x1=0 and 0≦y1≦0.3; and a barrier layer made of a second group-III nitride having a composition of InAlGaN at least containing In and Al. The composition of the second group-III nitride is, in a ternary phase diagram for InN, AlN, and GaN, in a certain range that is determined in accordance with the composition of the first group-III nitride. The barrier layer has a thickness of 3 nm or less. A low-crystallinity insulating layer is further formed on the barrier layer. The low-crystallinity insulating layer is made of silicon nitride and has a thickness of 3 nm or less.