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:
Nov. 08, 2011
Filed:
May. 26, 2006
Ken Nakahara, Kyoto, JP;
Norikazu Ito, Kyoto, JP;
Kazuaki Tsutsumi, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
Provided is a nitride semiconductor light emitting element having an improved carrier injection efficiency from a p-type nitride semiconductor layer to an active layer by simple means from a viewpoint utterly different from the prior art. A buffer layer, an undoped GaN layer, an n-type GaN contact layer, an InGaN/GaN superlattice layer, an active layer, a first undoped InGaN layer, a second undoped InGaN layer, and a p-type Gan-based contact layerare stacked on a sapphire substrate. A p-electrodeis formed on the p-type Gan-based contact layer. An n-electrodeis formed on a surface where the n-type GaN contact layeris exposed as a result of mesa-etching. The first undoped InGaN layeris formed to contact a well layer closest to a p-side in the active layer having a quantum well structure, and subsequently the second undoped InGaN layeris formed thereon. The carrier injection efficiency into the active layercan be improved by making the total film thickness of the first and second undoped InGaN layers 20 nm or less.