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. 25, 2013
Filed:
Mar. 16, 2011
Fumitake Nakanishi, Itami, JP;
Yoshiki Miura, Itami, JP;
Fumitake Nakanishi, Itami, JP;
Yoshiki Miura, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka-shi, Osaka, JP;
Abstract
Assuming that r (m) represents the radius of a GaN substrate, t(m) represents the thickness of the GaN substrate, h(m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t(m) represents the thickness of an AlGaN layer, h(m) represents a warp of the epitaxialwafer, arepresents the lattice constant of GaN and arepresents the lattice constant of AlN, the value tfound by the following expression is decided as the minimum thickness (t) of the GaN substrate:(1.5×101+1.2×102)×{1/(1.5×101)+1/(1.2×102)}/{15.96××(1−2/1)}×(1+2)+(1×2)/{5.32××(1−2/1)}−()/2=0A GaN substrate having a thickness of at least this minimum thickness (t) and less than 400 μm is formed.