| 摘要 |
[Problem] To provide an epitaxial silicon wafer in which enhanced diffusion of boron in a silicon substrate can be suppressed even when oxygen precipitates grow due to a discretionary heat treatment in a device process. [Solution] This epitaxial silicon wafer 10 comprises a silicon substrate 11 doped with boron, and an epitaxial layer 13 formed on a surface of the silicon substrate 11, wherein: the boron concentration in the silicon substrate is from 2.7×1017 atoms/cm3 to 1.3×1019 atoms/cm3 inclusive; and the initial oxygen concentration in the silicon substrate is less than or equal to 11×1017 atoms/cm3. When this epitaxial silicon wafer 10 is subjected to, for example, an oxygen precipitate evaluation heat treatment in which a heat treatment at 700°C for 3 hours and a heat treatment at 1000°C for 16 hours are performed in order, the oxygen precipitate density in the silicon substrate 11 is less than or equal to 1×1010/cm3. |
