Seed substrate for epitaxial growth use and method for manufacturing same, and semiconductor substrate and method for manufacturing same

A seed substrate for epitaxial growth comprising:

• a support substrate;
• a planarizing layer provided on an upper surface of the support substrate,
• the planarizing layer having a thickness of 0.5 to 3.0 μm;
• and
• a seed crystal layer provided on an upper surface planarizing layer,
• wherein the support substrate comprises:
• a core formed by group III nitride polycrystalline ceramics;
• and
• an encapsulating layer that encapsulates the core, the encapsulating layer having a thickness of 0.05 to 1.5 μm, and
• the seed crystal layer has oxidation-induced stacking faults of no more than 10 defects/cm2, and
• the thickness of the seed crystal layer is 0.1 to 1.5 μm.

A manufacturing method of seed substrate for epitaxial growth comprising:

• preparing a core consisting of group III nitride polycrystalline ceramics;
• obtaining a support substrate by depositing an encapsulating layer so as to wrap the core, the encapsulating layer having a thickness of 0.05 to 1.5 μm;
• depositing a planarizing layer on an upper surface of the support substrate, the planarizing layer having a thickness of 0.5 to 3.0 μm;
• and
• providing a seed crystal layer by thin-film transfer of 0.1 to 1.5 μm of the surface layer of Si<111> single crystal with oxidation-induced stacking faults of no more than 10 defects/cm2 on the top surface of the planarizing layer.