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:
Jul. 19, 2011
Filed:
Aug. 05, 2009
Yoshitaka Kuraoka, Anjo, JP;
Makoto Miyoshi, Inazawa, JP;
Shigeaki Sumiya, Handa, JP;
Mitsuhiro Tanaka, Handa, JP;
Yoshitaka Kuraoka, Anjo, JP;
Makoto Miyoshi, Inazawa, JP;
Shigeaki Sumiya, Handa, JP;
Mitsuhiro Tanaka, Handa, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A buffer layer formed of InAlGaN formed on a base, with an upper part of the buffer layer containing columnar polycrystalline including a grain boundary existing in a direction substantially perpendicular to a surface of the base. The number of grain boundaries in the lower part of the buffer layer is greater than that in the upper part, and a full width at half maximum of an X-ray rocking curve of the upper part is 300-3000 seconds, RMS of the surface of the buffer layer is 0.2 nm-6 nm, and the ratio of the grain boundary width of the crystal grain of the upper part in a direction parallel to the base surface to the formation thickness of the buffer layer is 0.5-1.5.