Nitride semiconductor light emitting device and fabrication method thereof

1. A semiconductor light emitting device comprising:

an n-type semiconductor layer;

an active layer formed on the n-type semiconductor layer;

a p-type semiconductor layer formed on the active layer, the p-type semiconductor layer comprising a p-type cladding layer formed on the active layer and a p-type contact layer formed on the p-type cladding layer;

an n-type electrode formed on the n-type semiconductor layer; and

a p-type electrode formed on the p-type semiconductor layer,

wherein a V-shaped distortion structure is formed at the n-type semiconductor layer and the active layer and the p-type semiconductor layer,

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,

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 bended toward the n-type semiconductor layer, respectively.

2. The semiconductor light emitting device according to claim 1 , further including an unevenness structure at an exposed surface of at least one side of the n-type a semiconductor layer and the p-type semiconductor layer.

3. The 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 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 semiconductor light emitting device according to claim 4 , wherein a surface of the p-type semiconductor layer is flat.

6. The semiconductor light emitting device according to claim 1 , wherein the n-type semiconductor layer includes:

an n-type GaN based semiconductor layer; and

an n-type super lattice layer or a multi-stacked layer.

7. The semiconductor light emitting device according to claim 6 , wherein the n-type super lattice layer 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 semiconductor light emitting device according to claim 1 , wherein the p-type semiconductor layer includes:

a p-type super lattice layer or a multi-stacked layer; and

a p-type GaN based semiconductor layer.

9. The semiconductor light emitting device according to claim 7 , wherein the p-type super lattice layer 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.

10. The semiconductor light emitting device according to claim 1 , further comprises a substrate formed on the lower surface of the n-type semiconductor layer.

11. The semiconductor light emitting device according to claim 10 , wherein the substrate is made of a material selected from a group consisting of sapphire, spinel (MgAl 2 0 4 ), SiC, Si, ZnO, GaAs and GaN.

12. The semiconductor light emitting device according to claim 10 , wherein the substrate includes at least one unevenness structure on a surface thereof.

13. The 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.

14. The 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 AlxInyGazN (0≦x, y, z≦1) with a different composition.