Nitride semiconductor light emitting device and fabrication method thereof
View Patent ↗The present invention relates to a GaN based nitride based light emitting device improved in Electrostatic Discharge (ESD) tolerance (withstanding property) and a method for fabricating the same including a substrate and a V-shaped distortion structure made of an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer on the substrate and formed with reference to the n-type nitride semiconductor layer.
1. A nitride semiconductor light emitting device comprising:
a substrate;
an n-type semiconductor layer formed on the substrate;
an active layer formed on the n-type semiconductor layer;
a p-type semiconductor layer formed on the active layer;
a transparent electrode formed on the p-type semiconductor layer;
an n-type electrode formed on an exposed portion of the n-type semiconductor layer; and
p-type bonding electrode formed on the transparent electrode,
wherein at least one of the n-type semiconductor layer and the p-type semiconductor layer further includes a super lattice layer or a multi-stacked layer; and
a V-shaped distortion structure is formed at least one portion of the active layer and the p-type semiconductor layer with reference to the n-type semiconductor layer,
wherein the p-type nitride semiconductor layer comprises a hole injection layer formed on the active layer and a p-type contact layer formed on the hole injection layer,
the V-shaped distortion structure is filled in an area between the p-type contact layer and the active layer, so that the lower surface of the p-type contact layer is flat, and
the upper and lower surfaces of the active layer in the V-shaped distortion are bent towards the n-type nitride semiconductor layer, respectively.
2. The nitride semiconductor light emitting device according to claim 1 , further including an unevenness structure at an exposed surface of at least one side of an n-type or a p-type semiconductor of the light emitting device after the substrate is removed.
3. The nitride semiconductor light emitting device according to claim 1 , wherein the V-shaped distortion structure includes a flat surface together with a sloped surface.
4. The nitride semiconductor light emitting device according to claim 1 , wherein the V-shaped distortion structure becomes smooth in shape, i.e., a valley shape, as approaching the active layer and the p-type semiconductor layer.
5. The nitride semiconductor light emitting device according to claim 4 , wherein a surface of the p-type semiconductor layer is flat.
6. The nitride semiconductor light emitting device according to claim 1 , wherein the super lattice layer is formed with a repeated structure of at least three layers, each of the layers is made of Al x In y Ga z N(0≦x, y, z≦1) with a different composition.
7. The nitride semiconductor light emitting device according to claim 1 , wherein the n-type super lattice is formed with a repeated structure of three layers, each of the three layers is made of an AlGaN layer, a GaN layer, and an InGaN layer, and at least one layer of the three layers has a thickness below 20 nm.
8. The nitride semiconductor light emitting device according to claim 1 , wherein the p-type super lattice is formed with a repeated structure of three layers, each of the three layers is made of an A 1 GaN layer, a GaN layer, and an InGaN layer, and at least one layer of the three layers has a thickness below 20 nm.