Crystalline multilayer structure and semiconductor device
Provided is a crystalline multilayer structure having good semiconductor properties. The crystalline multilayer structure includes a base substrate and a corundum-structured crystalline oxide semiconductor thin film disposed directly on the base substrate or with another layer therebetween. The crystalline oxide semiconductor thin film is 0.1 μm or less in a surface roughness (Ra).
1. A crystalline multilayer structure comprising:
a base substrate; and
a corundum-structured crystalline oxide semiconductor thin film disposed directly on the base substrate or with another layer therebetween, wherein
a surface roughness (Ra) of the crystalline oxide semiconductor thin film is 0.1 μm or less; and
a thickness of the crystalline oxide semiconductor thin film is 1 μm or more.
2. The crystalline multilayer structure of claim 1 , wherein the crystalline oxide semiconductor thin film comprises an abnormal grain inhibitor containing at least one selected from Br and I.
3. The crystalline multilayer structure of claim 1 , wherein the crystalline oxide semiconductor thin film comprises at least gallium.
4. The crystalline multilayer structure of claim 1 , wherein the thickness is 1 to 20 μm.
5. The crystalline multilayer structure of claim 1 , wherein the base substrate is a c-plane sapphire substrate.
6. A semiconductor device comprising the crystalline multilayer structure of claim 1 .