Patent ID: 8357939

Claim:
A silicon wafer comprising BMDs with a diagonal length of 10 nm to 50 nm, the diagonal length being the length in a <100> direction in a plane image of a BMD projected orthogonally to any one of the {110} planes, wherein a density of said BMDs at a depth position equal to or deeper than 50 μm from a surface of the silicon wafer is greater than or equal to 1×10 11 /cm 3 , and a ratio of {111} plane in total planes surrounding the BMDs is less than or equal to 0.3, wherein the ratio is determined as the ratio of length of the {111} plane to total length of the circumference, when a BMD is projected in a <110> direction, wherein the silicon wafer has a nitrogen concentration of 1.5×10 14 to 5×10 15 atoms/cm 3 , a carbon concentration of 3×10 15 to 2×10 17 atoms/cm 3 , and an oxygen concentration of 8×10 17 to 9×10 17 atoms/cm 3 , and wherein the silicon wafer is derived from a silicon single crystal pulled from a crystal pulling furnace.