Flip chip type nitride semiconductor light emitting device
View Patent ↗The present invention relates to a flip chip type nitride semiconductor light emitting device having p-type and n-type nitride semiconductor layers, and an active layer in between. The invention also has an ohmic contact layer formed on the p-type nitride semiconductor layer, a light-transmitting conductive oxide layer formed on the ohmic contact layer, and a highly reflective metal layer formed on the light-transmitting conductive oxide layer.
1. A flip chip type nitride semiconductor light emitting device comprising:
p-type and n-type semiconductor layers;
an active layer formed between the p-type and n-type semiconductor layers;
an ohmic contact layer formed on the p-type nitride semiconductor layer;
a light-transmitting conductive oxide layer formed on the ohmic contact layer;
a highly reflective metal layer formed on the light-transmitting conductive oxide layer; and
a diffusion prevention layer formed between the light-transmitting conductive oxide layer and the highly reflective metal layer,
wherein the highly reflective metal layer is made of at least one selected from a group including Al, Ag and alloys thereof, and the diffusion prevention layer is made of a material selected from a group consisting of Cu, Mo, V, W and alloy thereof including Ti—W alloy.
2. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer comprises an In 2 O 3 layer containing at least one selected from a group including Cu, Zn, and Mg.
3. The flip chip type nitride semiconductor light emitting device according to claim 2 , wherein the ohmic contact layer has a thickness of about 5 to 500 Å.
4. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer is made of an alloy selected from a group including MnNi, LaNi 5 , ZnNi, MgNi, and ZnMg.
5. The flip chip type nitride semiconductor light emitting device according to claim 4 , wherein the ohmic contact layer has a thickness of about 5 to 500 Å.
6. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer is made of at least one selected from a group including Rh, Ru, Pt, Pd, Ir, Ni, Co and alloys thereof.
7. The flip chip type nitride semiconductor light emitting device according to claim 6 wherein the ohmic contact layer has a thickness of about 5 to 500 Å.
8. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the light-transmitting conductive oxide layer is composed of at least one selected from a group including Indium Tin Oxide (ITO), ZnO, and MgO.
9. The flip chip type nitride semiconductor light emitting device according to claim 8 , wherein the light-transmitting conductive oxide layer has a thickness of about 0.1 to 1 μm.
10. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the ohmic contact layer comprises an In 2 O 3 layer containing Cu, and the light-transmitting conductive oxide layer comprises an ITO layer.
11. The flip chip type nitride semiconductor light emitting device according to claim 10 , wherein the highly reflective metal layer is made of Al.
12. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the highly reflective metal layer has a thickness of at least 0.1 μm.
13. The flip chip type nitride semiconductor light emitting device according to claim 1 , wherein the diffusion prevention layer has a thickness of about 10 to 10000 Å.
14. The flip chip type nitride semiconductor light emitting device according to claim 1 , further comprising a bumping buffer layer made of W or alloy thereof on the highly reflective metal layer.