Semiconductor light emitting device having a p-type semiconductor layer with a p-type impurity

摘要

According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting part, and a p-side electrode. The light emitting part is provided between the n-type and the p-type semiconductor layers, and includes a plurality of barrier layers and a plurality of well layers. The p-side electrode contacts the p-type semiconductor layer. The p-type semiconductor layer includes first, second, third, and fourth p-type layers. The first p-type layer contacts the p-side electrode. The second p-type layer contacts the light emitting part. The third p-type layer is provided between the first p-type layer and the second p-type layer. The fourth p-type layer is provided between the second p-type layer and the third p-type layer. The second p-type layer contains Al and contains a p-type impurity in a lower concentration lower than that in the first concentration.

主权项

1. A semiconductor light emitting device comprising:
a first semiconductor layer of a first conductivity-type; a second semiconductor layer of a second conductivity-type; a light emitting part provided between the first semiconductor layer and the second semiconductor layer, the light emitting part including a plurality of barrier layers and a plurality of well layers, the well layers including In; and an electrode contacting the second semiconductor layer, the second semiconductor layer including: a first region contacting the electrode and containing an impurity of the second conductivity-type in a first concentration; a second region contacting the light emitting part, containing Al and containing an impurity of the second conductivity-type in a second concentration lower than the first concentration; a third region provided between the first region and the second region, the third region containing an impurity of the second conductivity-type in a third concentration lower than the second concentration; and a fourth region provided between the second region and the third region, the fourth region having a concentration of an impurity of the second conductivity-type decreasing from the second concentration to the third concentration along a first direction from the first semiconductor layer toward the second semiconductor layer, wherein the first region is a GaN, the second region is an AlGaN, the third region is a GaN, and the fourth region is a GaN; wherein the first region is thinner than the third region, and thinner than the fourth region; wherein the second region is thinner than the third region, and thinner than the fourth region; wherein the third region has not less than 10 nanometers thickness; wherein the third concentration is not less than 1×1019 cm−3 and less than 2.5×1019 cm−3; wherein the third concentration is constant and has a variation within plus minus 20% of an average value of the third concentration; and wherein the third concentration has the lowest concentration of the impurity of the second conductivity-type in the second semiconductor layer.