| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of crystal defects with eccentricity of the single crystal reduced by equipping the single crystal machine with independently operated wire length controlling mechanisms for independently controlling a plurality of a single crystal-lifting and lowering wires in their lengths. SOLUTION: This single crystal-pulling machine is equipped with a means for holding a single crystal 9 and a single crystal holding unit 11 that is lifted and lowered by a plurality of lifting wires W1, W2, W3 and the like. This single crystal pulling machine is equipped with wire-length controlling units 13 for every wire W1, W2, at least one fewer than the whole ones independently from each other among a plurality of the lifting wires W1, W2, W3, with a laser displacement meter 15 for measuring the eccentricity of the single crystal 9 held by the holding unit 11, and with a wire length controlling unit 13 that outputs the commands to individual wire-length controlling units 13 based on the measured displacement to minimize the eccentricity of the single crystal. Consequently, the wires W1 and W2 can be controlled in their lengths on the basis of the wire W3 according to the eccentricity.
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