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.

Date of Patent:
Jun. 25, 2024

Filed:

Mar. 18, 2021
Applicant:

Asahi Kasei Kabushiki Kaisha, Tokyo, JP;

Inventors:

Kosuke Sato, Tokyo, JP;

Motoaki Iwaya, Nagoya, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/02 (2006.01);
U.S. Cl.
CPC ...
H01L 21/0254 (2013.01); H01L 21/02505 (2013.01);
Abstract

Provided is a nitride semiconductor element that does not cause element breakdown even when driven at high current density. A nitride semiconductor element includes an active layer, an electron block layer formed above the active layer, an AlGaN layer formed on the electron block layer, and a cover layer covering an upper surface of the AlGaN layer and formed of AlGaN or GaN having a lower Al composition ratio than in the AlGaN layer, in which the AlGaN layer includes protrusions provided on a surface opposite to the active layer, and the cover layer covers the protrusions. The AlGaN layer is preferably formed of AlGaN having an Al composition ratio decreasing in a direction away from the active layer, and the protrusions preferably have a frustum shape.


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