SILICON CARBIDE SUBSTRATE, EPITAXIAL LAYER PROVIDED SUBSTRATE, SEMICONDUCTOR DEVICE, AND METHOD FOR MANUFACTURING SILICON CARBIDE SUBSTRATE

摘要

The present invention provides a silicon carbide substrate, an epitaxial layer provided substrate, a semiconductor device, and a method for manufacturing the silicon carbide substrate, each of which achieves reduced on-resistance. The silicon carbide substrate is a silicon carbide substrate having a main surface, and includes: a SiC single-crystal substrate formed in at least a portion of the main surface; and a base member disposed to surround the SiC single-crystal substrate. The base member includes a boundary region and a base region. The boundary region is adjacent to the SiC single-crystal substrate in a direction along the main surface, and has a crystal grain boundary therein. The base region is adjacent to the SiC single-crystal substrate in a direction perpendicular to the main surface, and has an impurity concentration higher than that of the SiC single-crystal substrate.