| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for reducing carbon concentration in a single crystal and preventing occurrence of dislocation even when a single crystal to be grown has a large diameter. SOLUTION: A single crystal pulling device is disclosed, which has a radiation shield 6 disposed above a crucible 3 and shielding a single crystal C against radiation heat, gas supply means 13, 14, 17 supplying an inert gas G from above the radiation shield 6 into the crucible 3, and discharge means 18, 19 discharging the inert gas G passing through the crucible 3 to the outside of a furnace 2. The radiation shield 6 is placed in such a manner that a gap area between the outer circumference of the shield 6 and the inner circumference of the crucible 3 at the nearest portion ranges from 10% to less than 35% of the liquid surface area of a melt M and that a gap dimension between the lower end of the radiation shield 6 and the melt liquid surface is smaller than the width dimension in a radial direction of the lower end face of the radiation shield 6. The inert gas G supplied to the crucible 3 by the gas supply means 13, 14, 17 is discharged by the discharge means 18, 19 via the gap formed by the placement of the radiation shield 6. COPYRIGHT: (C)2009,JPO&INPIT
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