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. 24, 2015
Filed:
Dec. 28, 2010
Ryuichi Toba, Tokyo, JP;
Yoshitaka Kadowaki, Tokyo, JP;
Meoung Whan Cho, Yongin, KR;
Seog Woo Lee, Hwasung, KR;
Pil Guk Jang, Hwasung, KR;
Ryuichi Toba, Tokyo, JP;
Yoshitaka Kadowaki, Tokyo, JP;
Meoung Whan Cho, Yongin, KR;
Seog Woo Lee, Hwasung, KR;
Pil Guk Jang, Hwasung, KR;
Dowa Electronics Materials Co., Ltd., Tokyo, JP;
Wavesquare Inc., Yongin, KR;
Abstract
The purpose of the present invention is to provide a good ohmic contact for an n-type Group-III nitride semiconductor. An n-type GaN layer and a p-type GaN layer are aequentially formed on a lift-off layer (growth step). A p-side electrode is formed on the top face of the p-type GaN layer. A copper block is formed over the entire area of the top face through a cap metal. Then, the lift-off layer is removed by making a chemical treatment (lift-off step). Then, a laminate structure constituted by the n-type GaN layer, with which the surface of the N polar plane has been exposed, and the p-type GaN layer is subjected to anisotropic wet etching (surface etching step). The N-polar surface after the etching has irregularities constituted by {10-1-1} planes. Then, an n-side electrode is formed on the bottom face of the n-type GaN layer (electrode formation step).