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. 18, 2025
Filed:
Dec. 10, 2019
Air Water Inc., Osaka, JP;
Sumito Ouchi, Nagano, JP;
Hiroki Sukuki, Nagano, JP;
Mitsuhisa Narukawa, Nagano, JP;
Keisuke Kawamura, Nagano, JP;
Air Water Inc., Osaka, JP;
Abstract
A compound semiconductor substrate has a Si (silicon) substrate, a first Al nitride semiconductor layer which is a graded layer formed on the Si substrate and whose Al concentration decreases as the distance from the Si substrate increases along the thickness direction, a GaN (gallium nitride) layer formed on the first Al nitride semiconductor layer and having a lower average Al concentration than the average Al concentration of the first Al nitride semiconductor layer, and a second Al nitride semiconductor layer formed on the GaN layer and having a higher average Al concentration than the average Al concentration of the GaN layer. The threading dislocation density at any position in the thickness direction within the second Al nitride semiconductor layer is lower than the threading dislocation density at any position in the thickness direction within the first Al nitride semiconductor layer.