Semiconductor light-emitting device and method of forming electrode
A semiconductor light-emitting device having an electrode that can be manufactured by a simple method and is unlikely to deteriorate, and a method for forming the electrode are provided. The semiconductor light-emitting device according to the present invention has a semiconductor layered structure having a light-emitting layer that emits light by supplying electric power and an electrode formed on the semiconductor layered structure. The electrode has a reflection layer that reflects light exiting from the light-emitting layer, a barrier layer formed on the upper side and side surface of the reflection layer, and a pad layer formed only on the top surface of the barrier layer.
1. A semiconductor light-emitting device comprising:
a semiconductor layered structure having a light-emitting layer that emits light upon supply of electric power and
an electrode formed on the semiconductor layered structure, wherein
the electrode comprises:
a reflection layer that reflects light exiting from the light-emitting layer and is made of Al,
a barrier layer formed on an upper side and a side surface of the reflection layer,
a pad layer that is formed only on a top surface of the barrier layer and is made of Au, wherein the reflection layer has a film thickness of 40 nm or more and 70 nm or less, and
a layer that is made of Ni and formed on a top surface of the pad layer.
2. The semiconductor light-emitting device according to claim 1 , wherein the barrier layer is made of a high melting point metal having a higher melting point than those of Al and Au.
3. The semiconductor light-emitting device according to claim 2 , wherein the barrier layer contains at least one of Pt, Mo and W.
4. The semiconductor light-emitting device according to claim 1 , wherein the barrier layer has a film thickness of 200 nm or more.
5. The semiconductor light-emitting device according to claim 1 , wherein the barrier layer has a film thickness of 300 nm or less.
6. The semiconductor light-emitting device according to claim 1 , wherein the barrier layer formed on the side surface of the reflection layer has a film thickness of 20 nm or more.
7. The semiconductor light-emitting device according to claim 1 , wherein
the electrode further comprises an adhesion layer that contacts with a top surface of the semiconductor layered structure, and
the reflection layer is formed on a top surface of the adhesion layer.
8. The semiconductor light-emitting device according to claim 7 , wherein
the adhesion layer is made of Ni, and has a film thickness of 4 nm or less.
9. The semiconductor light-emitting device according to claim 7 , wherein
the adhesion layer is made of Ni, and has a film thickness of 2 nm or more.
10. The semiconductor light-emitting device according to claim 1 , wherein
the electrode further comprises a layer that is made of Ni and formed between the reflection layer and the barrier layer.
11. A semiconductor light-emitting device comprising:
a semiconductor layered structure having a light-emitting layer that emits light upon application of electric power and
an electrode formed on the semiconductor layered structure, wherein
the electrode comprises:
a reflection layer that reflects light exiting from the light-emitting layer and is made of Al,
a barrier layer formed on an upper side and a side surface of the reflection layer,
a pad layer formed only on a top surface of the barrier layer and is made of Au, wherein the barrier layer formed on the upper side of the reflection layer has a film thickness of 200 nm or more, and the barrier layer formed on the side surface of the reflection layer has a film thickness of 20 nm or more, and
a layer that is made of Ni and formed on a top surface of the pad layer.
12. The semiconductor light-emitting device according to claim 11 , wherein the reflection layer has a film thickness of 40 nm or more and 70 nm or less.
13. The semiconductor light-emitting device according to claim 11 , wherein the barrier layer is made of a high melting point metal having a higher melting point than those of Al and Au.
14. The semiconductor light-emitting device according to claim 13 , wherein the barrier layer contains at least one of Pt, Mo and W.
15. The semiconductor light-emitting device according to claim 11 , wherein the barrier layer has a film thickness of 300 nm or less.
16. The semiconductor light-emitting device according to of claim 11 , wherein
the electrode further comprises an adhesion layer that contacts with a top surface of the semiconductor layered structure, and
the reflection layer is formed on a top surface of the adhesion layer.
17. The semiconductor light-emitting device according to claim 16 , wherein
the adhesion layer is made of Ni, and has a film thickness of 4 nm or less.
18. The semiconductor light-emitting device according to claim 16 , wherein
the adhesion layer is made of Ni, and has a film thickness of 2 nm or more.
19. The semiconductor light-emitting device according to claim 11 , wherein
the electrode further comprises a layer that is made of Ni and formed between the reflection layer and the barrier layer.