SINGLE-CRYSTAL SILICON CARBIDE SUBSTRATE, EPITAXIAL SILICON CARBIDE SUBSTRATE, AND PROCESSES FOR PRODUCING SAID SUBSTRATES

摘要

A single-crystal silicon carbide substrate (1) which includes a first main surface (1b) and a second main surface (1a) on the reverse side from the first main surface (1b). The first main surface (1b) has a maximum diameter of 100 mm or larger. The first main surface (1b) includes a first central region (IRb), which is the first main surface (1b) excluding a region (ORb) extending from the periphery to 3 mm inward therefrom. When the first central region (IRb) is divided into first square regions in each of which each side has a length of 250 µm, the first square regions each have an arithmetic average roughness (Sa) less than 0.2 nm and have an oxygen concentration of 5 at.% or higher but less than 20 at.%. Thus, a single-crystal silicon carbide substrate and an epitaxial silicon carbide substrate which are effective in reducing the occurrence of vacuum holding failures are provided, and processes for producing the substrates are provided.