Flip chip type nitride semiconductor light emitting device and manufacturing method thereof
View Patent ↗Disclosed herein are a flip chip type nitride semiconductor light emitting device, which comprises a substrate for growing a nitride semiconductor material, an n-type nitride semiconductor layer formed on the substrate, an active layer formed on at least a part of the n-type nitride semiconductor layer, a p-type nitride semiconductor layer formed on the active layer, a bonding force providing layer formed on the p-type nitride semiconductor layer and adapted to provide a bonding force relative to the p-type nitride semiconductor layer, a reflective electrode layer formed on the bonding force providing layer, and adapted to reflect light produced in the active layer toward the substrate and to diffuse electric current, and a cap layer formed on the reflective electrode layer, and adapted to provide a bonding force between the reflective electrode layer and a bonding metal and to reduce contact resistance.
1. A flip chip type nitride semiconductor light emitting device comprising:
a) a substrate for growing a nitride semiconductor material;
b) an n-type nitride semiconductor layer formed on the substrate;
c) an active layer formed on at least a part of the n-type nitride semiconductor layer;
d) a p-type nitride semiconductor layer formed on the active layer;
e) a bonding force providing layer formed directly on the p-type nitride semiconductor layer and configured to provide a bonding force relative to the p-type nitride semiconductor layer;
f) a reflective electrode layer formed on the bonding force providing layer, and configured to reflect light produced in the active layer toward the substrate and to diffuse electric current; and
g) a cap layer formed on the reflective electrode layer, and configured to provide a bonding force between the reflective electrode layer and a bonding metal and to reduce contact resistance;
wherein the bonding force providing layer is made of one metal or alloys of two or more metals selected from the group consisting of Ni, Co, Pd, Ir, Rh, Ru, Zn, Mg and Sn;
wherein the reflective electrode layer is made of one metal or alloys of two or more metals selected from the group consisting of Ag, Rh and Al; and
wherein the cap layer is made of one metal selected from the group consisting of Pt and Pd.
2. The device of claim 1 , wherein the bonding force providing layer has a thickness of from 5 Å to 50 Å.
3. The device of claim 1 , wherein the reflective electrode has a thickness of from 500 Å to 5,000 Å.
4. The device of claim 1 , wherein the cap layer has a thickness of 100 Å or more while being smaller than that of the reflective layer.
5. The device of claim 1 , wherein the n-type nitride semiconductor layer comprises a composition being the formula:
A1 x In y Ga (1-x-y) N
wherein
0≦x≦1, 0≦y≦1
and
0≦ x+y ≦1.
6. The device of claim 5 , wherein the composition comprises GaN.
7. The device of claim 1 , wherein the active layer has a quantum well structure.
8. The device of claim 7 , wherein the active layer is made of GaN.
9. The device of claim 7 , wherein the active layer is made of InGaN.