| 摘要 |
PROBLEM TO BE SOLVED: To suppress the formation of vacancies and reduce the density of an oxygen deposit in a single crystal by introducing hydrogen at a specific concentration into the system for growing the crystal according to the Czochralski process and further introducing nitrogen thereinto. SOLUTION: A crystal is grown while continuously introducing hydrogen gas at 3% to 0.1 ppm concentration expressed in terms of volume ratio into an atmosphere when the silicon single crystal is grown according to the Czochralski process. Furthermore, nitrogen in an amount of 1×1016 to 1.5×1019 atoms/cm3 is contained in the silicon melt to grow the silicon single crystal. The crystal defect density having >=0.1μm size expressed in terms of diameter is preferably 1×108 to 1×109 defects/cm3 in the thickness center of a silicon wafer prepared from the resultant silicon single crystal. The obtained silicon wafer is then heat-treated at about 1,000-1,300 deg.C temperature in a nonoxidizing atmosphere for >=1 h to produce a silicon semiconductor substrate.
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