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:
Jun. 18, 2013
Filed:
Jun. 09, 2008
Takayuki Suzuki, Hitachi, JP;
Takeshi Meguro, Kitaibaraki, JP;
Takeshi Eri, Hitachi, JP;
Hitachi Cable, Ltd., Tokyo, JP;
Abstract
A nitride semiconductor free-standing substrate includes a nitride semiconductor crystal and an inversion domain with a density of not less than 10/cmand not more than 600/cmin a section parallel to a surface of the substrate and inside the substrate. A method for making the nitride semiconductor free-standing substrate includes a nitride semiconductor crystal growth step of growing on a heterosubstrate a nitride semiconductor crystal including an inversion domain with a density of not less than 10/cmand not more than 600/cmby adjusting a growth condition at an initial growth stage of the nitride semiconductor crystal, and a separation step for separating the grown nitride semiconductor crystal from the heterosubstrate to form the nitride semiconductor free-standing substrate.