Patent ID: 7229494

Claim:
A method for producing a compound semiconductor single crystal by a liquid encapsulated Czochralski method, comprising: containing a semiconductor raw material and an encapsulating material in a raw material melt-containing portion comprising a first crucible and a second crucible, the first crucible having a bottom and a cylindrical shape, and the second crucible being disposed in an inside of the first crucible and having a bottom portion thereof provided with a communication hole communicating with the first crucible; melting the raw material by heating the raw material melt-containing portion; and growing a crystal by making a seed crystal be in contact with a surface of the raw material melt in a state covered with the encapsulating material and by pulling up the seed crystal, wherein a crucible having a tapered structure in which an inner diameter of a bottom portion of the crucible is smaller than an inner diameter of a top portion of the crucible and in which a side face thereof tilted with respect to a vertical direction within a range of 0.2° to 10° C., and a diameter of a communication hole may be not more than ⅕ of the inner diameter of the crucible may be used as the second crucible, and when the body of a crystal is grown, a heater temperature is controlled so that on an interface between a growing crystal and the raw material melt, the crystallization is advanced until reaching an inner wall of the second crucible, and the crystallization is done in such a way that a diameter of the body of the growing crystal is consistent with an inner diameter of the second crucible on the interface and the diameter of the body of the growing crystal is confined by the inner wall of the second crucible, while the crystal is grown by maintaining a surface of the growing crystal in a state covered with the encapsulating material until termination of crystal growth.