Apparatus for preparing a single crystal of silicon

Abstract

The present invention relates to an apparatus for preparing a single crystal of silicon by which a high-quality single crystal of silicon can be prepared by changing the rotation rate of a crucible or a seed and a process for preparing a single crystal of silicon thereby. As compared with a conventional apparatus employing Czochralski method, which comprises a rotating axis of seed, a seed, a crucible, a heater, a rotary axis of crucible, a chamber and an adiabatic layer, the apparatus of the present invention is characterized by the improvement comprising means for controlling the rotation rate of the crucible or the seed, each of which consists of a D.C. voltage, a function generator, a voltage summing circuit and a stepping motor.