Method for manufacturing silicon carbide epitaxial substrate and silicon carbide semiconductor device

摘要

The silicon carbide epitaxial substrate has a silicon carbide substrate, a silicon carbide epitaxial film, and a composite defect.Compound defects include extended defects and basal plane dislocations.The extended defect comprises a first region extending from the origin point at the boundary of the silicon carbide substrate and the silicon carbide epitaxial film in the < 11-20 > direction and a second region extending along the < 1-100 > direction.The width of the first region in the < 1-100 > direction extends from the starting point toward the second region.The basal plane dislocation has a third region extending along the origin and extending along the < 1-100 > direction and a fourth region extending along the direction crossing the < 1-100 > direction.When the area of the main surface is defined as the first area and the area of the quadrangle tangent to the composite defect is the second area, the value obtained by dividing the second area by the first area is 0.001 or less.