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:
Nov. 02, 2010
Filed:
Apr. 03, 2007
Applicants:
Shunsuke Fujita, Itami, JP;
Hitoshi Kasai, Itami, JP;
Inventors:
Shunsuke Fujita, Itami, JP;
Hitoshi Kasai, Itami, JP;
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 23/58 (2006.01);
U.S. Cl.
CPC ...
Abstract
A GaN crystal substrate has a crystal growth surface on which a crystal is grown, and a rear surface opposite to the crystal growth surface. The crystal growth surface has a roughness Raof at most 10 nm, and the rear surface has a roughness Raof at least 0.5 μm and at most 10 μm. A ratio Ra/Raof the surface roughness Rato the surface roughness Rais at least 50. Thus, a GaN crystal substrate of which front and rear surfaces are distinguishable from each other is provided, without impairing the morphology of a semiconductor layer grown on the GaN crystal substrate.