SILICON CARBIDE SEMICONDUCTOR SUBSTRATE, METHOD FOR MANUFACTURING THE SAME, AND METHOD FOR MANUFACTURING SILICON CARBIDE SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a silicon carbide semiconductor substrate having high flatness even at a high temperature, a method for manufacturing the same, and a method for manufacturing a silicon carbide semiconductor device.SOLUTION: A silicon carbide semiconductor substrate 10 comprises: a base substrate 1 having a main surface 1A with an outer diameter of equal to or more than 100 mm and consisting of a single crystal silicon carbide; and an epitaxial layer 2 formed on the main surface 1A, and a trench 9 is formed on a main surface 2A of the epitaxial layer 2 or a back surface 1B on the side opposite to the main surface 1A of the base substrate 1. Thereby deformation of the substrate (for example, warpage of the substrate at high temperature processing) can be restricted by the trench 9. Thereby when the method for manufacturing the silicon carbide semiconductor device is performed by using the silicon carbide semiconductor substrate 10, a risk that an abnormality such as a crack on the silicon carbide semiconductor substrate 10 in the manufacturing process occurs, can be reduced.