| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon single crystal having a long bulk lifetime, usable preferably for a silicon substrate for high-proof pressure IGBT, having a low carbon concentration, and produced by Czochralski method.SOLUTION: Concerning a silicon single crystal, at least in a crystal straight trunk part in which a solidification ratio of the crystal pulled up by Czochralski method is 90% or less, a carbon concentration is 1.0×10atoms/cmor lower, and a bulk lifetime measured by a photoconductivity decay method is 30 msec or longer.SELECTED DRAWING: Figure 1 |
