METHOD FOR PULLING SINGLE CRYSTAL

PROBLEM TO BE SOLVED: To provide a method for pulling a single crystal by which, when pulling a large diameter single crystal, a neck part formed in the single crystal can be prevented from being broken and the propagation of heat shock dislocation from a seed crystal to the straight body part can be prevented. SOLUTION: When a plurality of diameter-enlarged parts 21 where the diameter of the neck part P1 is enlarged and diameter-reduced parts 22b where the diameter of the neck part P1 is reduced are formed in the neck part P1 by alternately forming the plurality of diameter-enlarged parts 21 and diameter-reduced parts 22, wherein each diameter-reduced part 22 is formed so that the minimum diameter in each diameter-reduced part 22 becomes a set value within the range of 4.0-6.0 mm, the variation width in the diameter difference between the maximum diameter d1 of each diameter-enlarged part 21 and the minimum diameter d2 of each diameter-reduced part 22 is controlled to be within the range of 0.5-2.0 mm, and the length dimension 1 of the neck part P1 is set to be within the range of 200-400 mm. COPYRIGHT: (C)2008,JPO&INPIT