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:
Jan. 28, 2014
Filed:
Oct. 02, 2012
Covalent Materials Corporation, Shinagawa-ku, JP;
Yoshihisa Abe, Hadano, JP;
Jun Komiyama, Hadano, JP;
Hiroshi Oishi, Hadano, JP;
Akira Yoshida, Hadano, JP;
Kenichi Eriguchi, Hadano, JP;
Shunichi Suzuki, Hadano, JP;
Covalent Material Corporation, Shinagawa-Ku, Tokyo, JP;
Abstract
A nitride semiconductor substrate is provided in which leak current reduction and improvement in current collapse are effectively attained when using Si single crystal as a base substrate. The nitride semiconductor substrate is such that an active layer of a nitride semiconductor is formed on one principal plane of a Si single crystal substrate through a plurality of buffer layers made of a nitride, in the buffer layers, a carbon concentration of a layer which is in contact with at least the active layer is from 1×10to 1×10atoms/cm, a ratio of a screw dislocation density to the total dislocation density is from 0.15 to 0.3 in an interface region between the buffer layer and the active layer, and the total dislocation density in the interface region is 15×10cmor less.