Light emitting device and method of manufacturing the same
A light emitting device and a method of manufacturing the same are provided. The light emitting device comprises a first conductive type lower semiconductor layer, a current diffusion layer, a first conductive type upper semiconductor layer, an active layer, and a second conductive type semiconductor layer. The current diffusion layer is formed on the first conductive type lower semiconductor layer. The first conductive type upper semiconductor layer is formed on the current diffusion layer. The active layer is formed on the first conductive type upper semiconductor layer. The second conductive type semiconductor layer is formed on the active layer.
1. A light emitting device comprising:
a first conductive type lower semiconductor layer;
a current diffusion layer on the first conductive type lower semiconductor layer, wherein the current diffusion layer comprises an uneven surface;
a first conductive type upper semiconductor layer on the current diffusion layer, wherein the first conductive type upper semiconductor layer comprises an uneven surface;
an active layer on the first conductive type upper semiconductor layer; and
a second conductive type semiconductor layer on the active layer,
wherein the first conductive type upper semiconductor layer is mixed with indium and tin impurities.
2. The light emitting device according to claim 1 , wherein the current diffusion layer comprises at least one of ITO, Co, W, and Fe.
3. The light emitting device according to claim 1 , comprising:
a first electrode directly on the first conductive type lower semiconductor layer; and
a second electrode on the second conductive type semiconductor layer.
4. The light emitting device according to claim 1 , comprising:
a first electrode directly on the current diffusion layer; and
a second electrode on the second conductive type semiconductor layer.
5. The light emitting device according to claim 1 , comprising:
a first electrode directly on the first conductive type upper semiconductor layer; and
a second electrode on the second conductive type semiconductor layer.
6. The light emitting device according to claim 1 , wherein the uneven surface of the current diffusion layer and the uneven surface of the first conductive type upper semiconductor layer are faced with each other.
7. The light emitting device according to claim 1 , wherein the first conductive type upper semiconductor layer has a different carrier concentration than the first conductive type lower semiconductor layer.
8. The light emitting device according to claim 1 , comprising:
a substrate formed under the first conductive type lower semiconductor layer, and
at least one of a buffer layer and an undoped nitride layer formed between the substrate and the first conductive type lower semiconductor layer.
9. The light emitting device according to claim 1 , wherein the current diffusion layer is directly on the first conductive type lower semiconductor layer.
10. A light emitting device comprising:
a substrate;
a first layer on the substrate, wherein the first layer has a conductivity;
an ITO layer on the first layer;
a second layer on the ITO layer, wherein the second layer comprises a first conductivity type semiconductor layer;
an active layer on the second layer; and
a third layer on the active layer, wherein the third layer comprises a second conductivity type semiconductor layer,
wherein the ITO layer has an uneven surface,
wherein the second layer is mixed with indium and tin impurities.
11. The light emitting device according to claim 10 , wherein at least a portion of the ITO layer is formed on the same horizontal plane with the second layer.
12. The light emitting device according to claim 10 , wherein the first conductivity type semiconductor layer comprises an n-type dopant and the second conductivity type semiconductor layer comprises a p-type dopant.
13. The light emitting device according to claim 10 , wherein the first layer, the second layer, and the third layer are formed of compound semiconductor layer materials.
14. The light emitting device according to claim 10 , wherein the substrate is formed of one of sapphire, SiC, and Si.
15. The light emitting device according to claim 10 , wherein the ITO layer is formed on an entire surface of the first layer.
16. The light emitting device according to claim 10 , wherein the ITO layer has a first thickness and a second thickness thicker than the first thickness.
17. The light emitting device according to claim 10 , wherein the ITO layer has a flat lower surface and a patterned upper surface.
18. The light emitting device according to claim 10 , wherein the second layer has a flat upper surface and an uneven lower surface.
19. A method of manufacturing a light emitting device, the method comprising:
forming a buffer layer on a substrate;
forming an undoped nitride layer;
forming a first conductive type lower semiconductor layer on the undoped nitride layer;
forming a current diffusion layer on the first conductive type lower semiconductor layer;
forming a first conductive type upper semiconductor layer on the current diffusion layer;
forming an active layer on the first conductive type upper semiconductor layer; and
forming a second conductive type semiconductor layer on the active layer,
wherein the first conductive type upper semiconductor layer is mixed with indium and tin impurities.