Crystalline multilayer oxide thin films structure in semiconductor device
Provided is a highly conductive crystalline multilayer structure including a corundum-structured crystalline oxide thin film whose resistance has not increased even after annealing (heating). The crystalline multilayer structure includes a base substrate and the corundum-structured crystalline oxide thin film disposed directly on the base substrate or with another layer therebetween. The crystalline oxide thin film is 1 μm or more in a thickness and 80 mΩcm or less in an electrical resistivity. A semiconductor device includes the crystalline multilayer structure.
1. A corundum-structured crystalline oxide film comprising:
metal elements that contain gallium (Ga),
in which the corundum-structured crystalline oxide film has a thickness of 1 μm or more and an electrical resistivity of 80 mΩcm or less, and
in which the corundum-structured crystalline oxide film has an atomic ratio of gallium (Ga) to all of the metal elements comprised in the corundum-structured crystalline oxide film to be 0.5 or more.
2. The corundum-structured crystalline oxide film of claim 1 , wherein the corundum-structured crystalline oxide film has a surface roughness (Ra) of 0.1 μm or less.
3. The corundum-structured crystalline oxide film of claim 1 , wherein the thickness of the corundum-structured crystalline oxide film is 1 μm to 20 μm.
4. The corundum-structured crystalline oxide film of claim 1 , wherein the corundum-structured crystalline oxide film contains a dopant.
5. The corundum-structured crystalline oxide film of claim 4 , wherein the dopant has a concentration that is 1E15/cm to 1E20/cm.
6. The corundum-structured crystalline oxide film of claim 5 , wherein the dopant contains at least one selected from Ge, Sn, Si, Ti, Zr, and Hf.
7. A semiconductor device comprising:
a corundum-structured crystalline oxide film comprising metal elements that contain gallium (Ga),
in which the corundum-structured crystalline oxide film has a thickness of 1 μm or more and an electrical resistivity of 80 mΩcm or less, and
in which the corundum-structured crystalline oxide film has an atomic ratio of gallium (Ga) to all of the metal elements comprised in the corundum-structured crystalline oxide film to be 0.5 or more.
8. The semiconductor device of claim 7 , wherein the corundum-structured crystalline oxide film has a surface roughness (Ra) of 0.1 μm or less.
9. The semiconductor device of claim 7 , wherein the thickness of the corundum-structured crystalline oxide film is 1 μm to 20 μm.
10. The semiconductor device of claim 7 , wherein the corundum-structured crystalline oxide film contains a dopant.
11. The semiconductor device of claim 10 , wherein the dopant has a concentration that is 1E15/cm 3 to 1E20/cm 3 .
12. The semiconductor device of claim 10 , wherein the dopant contains at least one selected from Ge, Sn, Si, Ti, Zr, and Hf.
13. The semiconductor device of claim 7 , further comprising:
an electrode that is electrically connected to the corundum-structured crystalline oxide film.
14. The semiconductor device of claim 13 , wherein the electrode is disposed on the corundum-structured crystalline oxide film.
15. The semiconductor device of claim 13 , wherein the electrode is an ohmic electrode.