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:
Aug. 22, 2023
Filed:
May. 13, 2019
Sumitomo Chemical Company, Limited, Tokyo, JP;
Fumimasa Horikiri, Ibaraki, JP;
Takeshi Kimura, Ibaraki, JP;
SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo, JP;
Abstract
There is provided a nitride crystal substrate having a main surface and formed of group-III nitride crystal, wherein N/N, satisfies formula (1) below, which is a ratio of a carrier concentration Nat a center of the main surface relative to a carrier concentration N: 0.5≤N/N≤1.5 . . . (1) where Nis the carrier concentration on the main surface side of the nitride crystal substrate obtained based on a reflectance of the main surface measured by a reflection type Fourier transform infrared spectroscopy, and Nis the carrier concentration in the nitride crystal substrate obtained based on a specific resistance of the nitride crystal substrate and a mobility of the nitride crystal substrate measured by an eddy current method.