Group III nitride semiconductor light-emitting device and production method therefor

摘要

The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved emission performance. A light-emitting layer has a MQW structure in which a plurality of layer units are repeatedly deposited, each layer unit comprising a well layer, a protective layer, and a barrier layer sequentially deposited. The protective layer has a layered structure comprising a second protective layer disposed in contact with and on the well layer, and a first protective layer disposed in contact with and on the second protective layer. The second protective layer is formed of GaN. The first protective layer is formed of AlGaInN. The first protective layer has a bandgap larger than that of the well layer and not larger than that of the barrier layer. Moreover, the first protective layer has an In composition ratio of more than 0% and not more than 4%.

主权项

1. A Group III nitride semiconductor light-emitting device having a multiple quantum well structure light-emitting layer,
wherein the light-emitting layer comprises a structure in which a plurality of layer units are repeatedly deposited, each layer unit comprising a well layer, a protective layer consisting of a first protective layer and a second protective layer on the well layer, and a barrier layer on the first protective layer sequentially deposited; wherein the well layer consists of InGaN; each of the first protective layer and the second protective layer has a bandgap larger than a bandgap of the well layer, and the second protective layer consists of GaN disposed in contact with and on the well layer and the first protective layer is disposed in contact with and on the second protective layer and in contact with the barrier layer, the first protective layer consisting of AlGaInN having an In composition ratio not less than 1.5% and not more than 3.5%; and the barrier layer consists of AlGaN; wherein the first protective layer and the second protective layer are grown at the same temperature as employed for the well layer, and the barrier layer is grown at a barrier growth temperature higher than a temperature employed for the well layer; wherein the first protective layer and the second protective layer covers the well layer to prevent the evaporation of In from the well layer while raising a temperature to the barrier growth temperature for forming the barrier layer after the formation of the well layer.