TECHNICAL FIELD

The disclosures herein relate to a silicon carbide epitaxial wafer.

The present application claims priority to International Application PCT/JP2017/031668 filed under the Patent Cooperation Treaty on Sep. 1, 2017, and claims priority to International Application PCT/JP2017/047289 filed under Patent Cooperation Treaty on Dec. 28, 2017. All the contents of the noted international applications are incorporated herein by reference.

BACKGROUND ART

A silicon carbide epitaxial wafer that has a silicon carbide epitaxial layer grown on a single-crystal silicon carbide substrate disposed in a convex form and has few crystal defects is disclosed as an example of silicon carbide epitaxial wafers (see Patent Document 1, for example).

RELATED-ART DOCUMENTS

Patent Document

[Patent Document 1] Japanese Patent Application Publication No. 2009-292705

SUMMARY OF THE INVENTION

According to one aspect of a present embodiment, a silicon carbide epitaxial wafer includes a single crystal silicon carbide substrate of 4H polytype having a major surface thereof inclined at an angle θ to a {0001} plane toward a <11-20> direction, and a silicon carbide epitaxial layer of a thickness t formed on the major surface. The diameter of the single crystal silicon carbide substrate is greater than or equal to 150 mm, and the angle θ exceeds 0°, and is less than or equal to 6°. One or more pairs of a screw dislocation pit and a diagonal line defect situated at a distance of t/tan θ from the pit are present in a surface of the silicon carbide epitaxial layer, and the density of the pairs of a pit and a diagonal line defect is less than or equal to 2 pairs/cm2.

