Light emitting device and method of manufacturing the same
A light emitting device is disclosed. The light emitting device includes a conductive support layer; a reflective layer disposed on the conductive support layer; a nitride semiconductor layer disposed on the reflective layer. Furthermore, the nitride semiconductor layer includes a second-type semiconductor layer on the reflective layer, an active layer on the second-type semiconductor layer, and a first-type semiconductor layer on the active layer; a light extraction structure disposed on the first-type semiconductor layer; and a first-type electrode disposed on the light extraction structure.
1. A light emitting device, comprising:
a conductive support layer;
a reflective layer disposed on the conductive support layer;
a nitride semiconductor layer disposed on the reflective layer, wherein the nitride semiconductor layer includes a second-type semiconductor layer on the reflective layer, an active layer on the second-type semiconductor layer, and a first-type semiconductor layer on the active layer;
a light extraction structure disposed on the first-type semiconductor layer; and
a first-type electrode disposed next to the light extraction structure.
2. The light emitting device of claim 1 , wherein the light extraction structure includes a plurality of cones.
3. The light emitting device of claim 2 , wherein a top of any of the cones is higher than a middle between a top surface of the first-type electrode and a bottom surface of the first-type electrode, on a top surface of the first-type semiconductor layer.
4. The light emitting device of claim 1 , wherein the conductive support layer includes a soft metal and a hard metal.
5. The light emitting device of claim 4 , wherein the soft metal includes Au, Cu, Ag, and Al.
6. The light emitting device of claim 4 , wherein the hard metal includes Ni, Co, Pt, and Pd.
7. The light emitting device of claim 1 , wherein the reflective layer includes a metal.
8. The light emitting device of claim 7 , wherein the metal includes Ni and Au.
9. The light emitting device of claim 1 , wherein the reflective layer has a specific contact resistance of 10-3 Ωcm2 to 10-4 Ωcm2.
10. The light emitting device of claim 2 , wherein the cones are disposed under and beside the first-type electrode.
11. The light emitting device of claim 2 , wherein at least one of the cones is a nano scale cone.
12. The light emitting device of claim 11 , wherein the nano scale cone has a size of 10 nm to 1000 nm.
13. The light emitting device of claim 2 , wherein the cones are made of a nitride semiconductor material.
14. The light emitting device of claim 13 , wherein the nitride semiconductor material of the cones has a formula of AlxInyGa(1-x-y)N (where, 0≦x≦1, 0≦y≦1, and 0≦x+y≦1).
15. The light emitting device of claim 2 , wherein the at least one of the cones is formed with a shape of a pyramid.
16. The light emitting device of claim 1 , wherein the active layer includes InGaN, and at least one of the first-type semiconductor layer or the second-type semiconductor layer includes AlGaN.
17. The light emitting device of claim 1 , wherein the light extraction structure includes substantially the same material as that of the nitride semiconductor layer.
18. The light emitting device of claim 1 , wherein the light extraction structure is a part of the nitride semiconductor layer.
19. The light emitting device of claim 2 , wherein the cones do not overlap each other.
20. The light emitting device of claim 1 , wherein the light extraction structure is disposed on an entire upper surface of the first-type semiconductor layer.