Diode having vertical structure and method of manufacturing the same
A light emitting diode includes a conductive layer, an n-GaN layer on the conductive layer, an active layer on the n-GaN layer, a p-GaN layer on the active layer, and a p-electrode on the p-GaN layer. The conductive layer is an n-electrode.
1. A light emitting device comprising:
a first metal layer comprising Au;
a first electrode on the first metal layer, the first electrode serving as a reflective layer;
a GaN-based semiconductor structure having a first surface on the first electrode, the semiconductor structure comprising a first-type layer, an active layer on the first-type layer, and a second-type layer on the active layer;
a second electrode on a second surface of the semiconductor structure, wherein the second surface is opposite the first surface; and
a second metal layer comprising Au on the second electrode,
wherein the first electrode and the second surface are configured such that the first electrode reflects light from the active layer back through the second surface, and wherein the first electrode and the second electrode are arranged on the opposite surfaces of the semiconductor structure, respectively, whereby enhancing brightness of the device, and
wherein the width of the first metal layer is greater than the width of the second metal layer.
2. The device according to claim 1 , wherein the first electrode comprises at least one of Al, Ti, Cr, and Au.
3. The device according to claim 1 , wherein the second electrode comprises at least one of Ni, Au, Pd, and Pt.
4. The device according to claim 1 , wherein the active layer comprises AllnGaN.
5. The device according to claim 1 , further comprising a cladding layer on the active layer.
6. The device according to claim 5 , wherein the cladding layer is arranged between the active layer and the second-type layer.
7. The device according to claim 5 , wherein the cladding layer comprises AIGaN.
8. The device according to claim 1 , wherein the first metal layer is configured to serve as a first pad.
9. The device according to claim 1 , wherein the second metal layer is configured to serve as a second pad.
10. The device according to claim 1 , wherein a thickness of the second metal layer is about 0.5 μm or higher.
11. The device according to claim 1 , further comprising a transparent layer on the semiconductor structure.
12. The device according to claim 11 , wherein the transparent layer comprises a transparent conductive layer.
13. The device according to claim 11 , the transparent layer comprises oxide.
14. The device according to claim 11 , wherein the transparent layer comprises indium-tin-oxide.
15. The device according to claim 1 , wherein the first-type is n-type and the second-type is p-type.
16. The device according to claim 1 , wherein the first-type layer is doped with Si.
17. The device according to claim 16 , wherein the doping concentration of Si is about 10 17 cm -3 or greater.
18. The device according to claim 1 , wherein the second-type layer is doped with Mg.
19. The device according to claim 18 , wherein the doping concentration of Mg is about 10 17 cm -3 or greater.
20. The device according to claim 1 , wherein the width of the first electrode is greater than the width of the second metal layer.