| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon wafer exhibiting high gettering effect to Cu, and capable of suppressing propagation of dislocation to the surface layer, even if dislocation is generated starting from a planar oxygen precipitate, in device process.SOLUTION: In a silicon wafer 1, a surface layer 1a1 at least to a depth of 5 μm from the surface has the LSTD density of less than 1.0 piece/cm. In a bulk part 1b excepting the surface layer 1a1, a planar oxygen precipitate 2a grows more dominantly than a polyhedral oxygen precipitate 2b. Between the surface layer 1a1 and the bulk part 1b, an intermediate layer 1a2 where the planar oxygen precipitate 2a does not grow is provided. The intermediate layer 1a2 has an oxygen density of 0.8-1.2×10atoms/cm. |
