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:
Feb. 08, 2005
Filed:
Apr. 26, 2001
Satoshi Tomioka, Kanagawa, JP;
Satoshi Tomioka, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
Provided is a method of forming a substrate with which a good-quality substrate having few cracks is obtained. On a growth base made of sapphire with a thickness of smaller than or equal to 100 μm, a GaN substrate is grown as heating the growth base, and cooling is provided therefor. At this time, the thickness of the substrate subject to growth is made larger than or equal to 200 μm and the curvature thereof is made smaller than or equal to 0.03 cm, the curvature being caused by the difference in thermal expansion coefficients of the growth base and the substrate. Thus, even though the substrate is warped due to the cooling after the growth, occurrence of crack in the substrate is prevented and the good-quality substrate is obtained.