| US 7,576,363 B2 | ||
| Group III nitride compound semiconductor light emitting device | ||
| Toshiya Uemura, Aichi (Japan); Katsuhisa Sawazaki, Aichi (Japan); Masahito Nakai, Aichi (Japan); and Yuhei Ikemoto, Aichi (Japan) | ||
| Assigned to Toyoda Gosei Co., Ltd., Nishikasugai-gun, Aichi (Japan) | ||
| Filed on Oct. 07, 2005, as Appl. No. 11/245,448. | ||
| Claims priority of application No. P2004-296706 (JP), filed on Oct. 08, 2004. | ||
| Prior Publication US 2006/0108603 A1, May 25, 2006 | ||
| Int. Cl. H01L 33/00 (2006.01) | ||
| U.S. Cl. 257—94 [257/101; 257/103; 257/79; 257/E33.01] | 21 Claims |
| 1. A group III nitride compound semiconductor light emitting device comprising:
an n-type semiconductor layer;
a p-type net conductivity semiconductor layer comprising a superlattice structure comprising a plurality of first and second
layers, said first layers comprising at least Al and said second layers having a composition differing from a composition
of the first layers, said plurality of first and second layers being laminated alternately and repetitively; and
an active layer interposed between the n-type semiconductor layer and the p-type net conductivity semiconductor layer,
wherein a layer of said first layers located closest to the active layer has an Al composition that is less than an Al composition
of other layers of said first layers,
wherein said layer of said first layers located closest to the active layer comprises one of:
no doping; and
a doping amount of a p-type impurity that is less than a doping amount of a p-type impurity of said other layers of said first
layers, and
wherein the first layers comprise AlGaN and the second layers comprise InGaN.
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