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:
May. 24, 2022
Filed:
Apr. 19, 2018
Sciocs Company Limited, Hitachi, JP;
Sumitomo Chemical Company, Limited, Tokyo, JP;
Fumimasa Horikiri, Hitachi, JP;
Takehiro Yoshida, Hitachi, JP;
SCIOCS COMPANY LIMITED, Hitachi, JP;
SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo, JP;
Abstract
There is provided a nitride crystal substrate comprising group-III nitride crystal and containing n-type impurities, wherein an absorption coefficient α is approximately expressed by equation (1) in a wavelength range of at least 1 μm or more and 3.3 μm or less: α=n Kλ(1) (wherein, λ(μm) is a wavelength, α(cm) is absorption coefficient of the nitride crystal substrate at 27° C., n (cm) is a free electron concentration in the nitride crystal substrate, and K and a are constants, satisfying 1.5×10≤K≤6.0×10, a=3).