Patent ID: 7288791

Claim:
An epitaxial wafer comprising: an epitaxial silicon layer on a surface of a wafer, wherein the wafer has a crystal plane orientation of (100) and is sliced from a silicon monocrystalline ingot that is doped with arsenic and has a resistivity of at least 2.5 mΩ·cm, and the slice is made at an angle θ in the [001] direction or [00 1 ] direction and an angle φ in the [010] direction or [0 1 0] direction with respect to the [100] axis, where 0.24°≦θ and φ≦0.1°, or 0.24°≦φ and θ≦0.1°, and wherein a pit density in the epitaxial silicon layer is less than 1 defect/in 2 .