Patent ID: 10020203

Abstract:
An epitaxial silicon wafer includes a silicon wafer consisting of a COP region in which a nitrogen concentration is 1×1012−1×1013 atoms/cm3, and an epitaxial silicon film formed on the silicon wafer. When heat treatment for evaluation is applied, a density of BMD formed inside the silicon wafer is 1×108−3×109 atoms/cm3 over the entire radial direction of the silicon wafer. An average density of the BMD formed in an outer peripheral region of the silicon wafer which is a 1-10 mm range separated inward from an outermost periphery thereof is lower than the average density of the BMD formed in a center region. A variation in the BMD density in the outer peripheral region is 3 or less, and a residual oxygen concentration in the outer peripheral region is 8×1017 atoms/cm3 or more.