Nitride semiconductor device, nitride semiconductor wafer, and method for manufacturing nitride semiconductor layer

1. A nitride semiconductor device comprising:

a first layer formed on an amorphous layer, wherein said first layer comprises aluminum nitride and has a compressive strain or an tensile strain; and

a functional layer formed on the first layer, wherein said functional layer comprises a nitride semiconductor,

wherein the first layer is provided on a second layer, the second layer being provided on the amorphous layer and having one of a face-centered cubic lattice structure and a body-centered cubic lattice structure.

2. The nitride semiconductor device according to claim 1 , wherein the first layer has a compressive strain.

3. The nitride semiconductor device according to claim 1 , wherein the functional layer comprises

a first semiconductor layer of a first conductivity type, the first semiconductor layer being formed on the first layer and comprising a nitride semiconductor,

a light emitting part provided on the first semiconductor layer, the light emitting part comprising a plurality of barrier layers and a well layer provided between the plurality of barrier layers, and

a second semiconductor layer of a second conductivity type different from the first conductivity type, the second semiconductor layer being provided on the light emitting part and comprising a nitride semiconductor.

4. The nitride semiconductor device according to claim 1 , wherein the amorphous layer is one of silicon oxide and amorphous silicon.

5. The nitride semiconductor device according to claim 1 , wherein the amorphous layer is an amorphous metal.

6. The nitride semiconductor device according to claim 1 , wherein the first layer is oriented in a direction perpendicular to a layer face of the first layer.

7. The nitride semiconductor device according to claim 1 , wherein the second layer comprises at least one of Al, Cu, Au, Ag, Ir, Ni, Pt, Mo and W.

8. A nitride semiconductor wafer comprising:

a substrate;

an amorphous layer provided on the substrate;

a first layer formed on an amorphous layer, wherein said first layer comprises aluminum nitride and has a compressive strain or an tensile strain;

a functional layer formed on the first layer, wherein said functional layer comprises a nitride semiconductor; and

a second layer provided between the amorphous layer and the first layer, and having one of a face-centered cubic lattice structure and a body-centered cubic lattice structure.

9. The nitride semiconductor wafer according to claim 8 , wherein the first layer has a compressive strain.

10. The nitride semiconductor wafer according to claim 8 , wherein the amorphous layer is one of silicon oxide and amorphous silicon.

11. The nitride semiconductor wafer according to claim 8 , wherein the first layer is oriented in a direction perpendicular to a layer face of the first layer.

12. The nitride semiconductor wafer according to claim 8 , wherein the second layer comprises at least one of Al, Cu, Au, Ag, Ir, Ni, Pt, Mo and W.

13. The nitride semiconductor wafer according to claim 8 , wherein the substrate is a silicon substrate.

14. A method for manufacturing a nitride semiconductor layer, comprising:

forming an amorphous layer on a substrate;

forming a first layer on the amorphous layer by sputtering, wherein the first layer comprises aluminum nitride and has a compressive strain or a tensile strain; and

forming a functional layer on the first layer, wherein the functional layer comprises a nitride semiconductor,

wherein the forming the first layer comprises

forming a second layer on the amorphous layer, the second layer having one of a face-centered cubic lattice structure and a body-centered cubic lattice structure, and

forming the first layer on the second layer.

15. The method for manufacturing the nitride semiconductor layer according to claim 14 , wherein

the first layer has a compressive strain, and

the substrate is a silicon substrate.