Nitride semiconductor light emitting device
View Patent ↗The invention provides a nitride semiconductor device and a manufacturing method thereof. In the invention, n-type and p-type nitride semiconductor layers are formed on a substrate, and an active layer is formed therebetween. The n-type nitride semiconductor layers include first and second n-type GaN layers disposed in the order of distance from the active layer. In addition, in the nitride semiconductor device of the invention, an Al x Ga l-x N layer, where 0<x<1, is interposed between the first and second n-type GaN layers, thereby forming a two-dimensional electron gas layer at interfaces of the first and second n-type GaN layers.
1. A nitride semiconductor light emitting device comprising:
a substrate;
a first n-type GaN layer, an Al x Ga l-x N layer (where 0<x<1), a second n-type GaN layer, an active layer and a p-type semiconductor layer sequentially formed on the substrate; and
an AIN layer disposed between the Al x Ga l-x N layer and the first or the second n-type GaN layer, wherein
two-dimensional electron gas layers are formed at interfaces between the first n-type GaN layer and the Al x Ga l-x N layer and between the Al x Ga l-x N layer and the second n-type GaN layer.
2. The nitride semiconductor light emitting device according to claim 1 , wherein the Al x Ga l-x N layer has a thickness of about 100 Å to 500 Å.
3. The nitride semiconductor light emitting device according to claim 1 , wherein the Al x Ga l-x N layer contains x in the range of about 0.05 to 0.5.
4. The nitride semiconductor light emitting device according to claim 1 , wherein the Al x Ga l-x N layer comprises an undoped Al x Ga l-x N layer.
5. The nitride semiconductor light emitting device according to claim 1 , wherein the AIN layer has a thickness of about 5 Å to 30 Å.
6. The nitride semiconductor light emitting device according to claim 1 , further comprising a GaN layer disposed between the substrate and the first n-type GaN layer, the GaN layer doped with less than 1 mol % Al.
7. The nitride semiconductor light emitting device according to claim 1 , wherein the nitride semiconductor light emitting device is mesa-etched to expose a partial area of the first n-type GaN layer.
8. The nitride semiconductor light emitting device according to claim 7 , wherein the exposed area of the mesa-etched n-type nitride semiconductor layer is substantially flush with the interface between the Al x Ga l-x N layer and the first n-type GaN layer where the two-dimensional electron gas layer is formed.
9. The nitride semiconductor light emitting device according to claim 7 , wherein the exposed area of the mesa-etched n-type nitride semiconductor layer is in a plane lower than that of the interface between the Al x Ga l-x N layer and the first n-type GaN layer where the two-dimensional electron gas layer is formed.
10. The nitride semiconductor light emitting device according to claim 1 , further comprising a undoped GaN layer formed between the first n-type GaN layer and the Al x Ga l-x N layer,
wherein the two-dimensional electron gas layer is formed at an interface between the undoped GaN layer and the Al x Ga l-x N layer.
11. The nitride semiconductor light emitting device according to claim 10 , wherein the nitride semiconductor light emitting device is mesa-etched to expose a partial area of the undoped GaN layer.
12. The nitride semiconductor light emitting device according to claim 10 , wherein the undoped GaN layer has a thickness of 80 Å to 200 Å.
13. The nitride semiconductor light emitting device according to claim 11 , wherein the undoped GaN layer has a thickness of 80 Å to 200 Å.
14. The nitride semiconductor device according to claim 1 , wherein the substrate is a conductive substrate,
the nitride semiconductor light emitting device having a vertical structure in which a first electrode is formed on a lower surface of the conductive substrate and a second electrode is formed on the p-type nitride semiconductor layer.