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. 04, 2020
Filed:
Dec. 08, 2016
Epistar Corporation, Hsinchu, TW;
Wen Hsiang Lin, Hsinchu, TW;
Chang-Hua Hsieh, Hsinchu, TW;
EPISTAR CORPORATION, Hsinchu, TW;
Abstract
A nitride-based semiconductor light-emitting device comprises a light-emitting stack comprising a first semiconductor structure having a first conductivity, a second semiconductor structure having a second conductivity, and an active region between the first semiconductor structure and the second semiconductor structure; a semiconductor buffer structure formed under the first semiconductor structure; an un-doped AlGaN layer formed between the first semiconductor structure and the semiconductor buffer structure; and a substrate under the semiconductor buffer structure, wherein the semiconductor buffer structure comprises an un-doped first layer under the un-doped AlGaN layer, and an un-doped second layer between the un-doped first layer and the substrate, and wherein the thickness of the un-doped first layer is thicker than that of the un-doped second layer and the un-doped AlGaN layer.