Shin-etsu Handotai Co., Ltd.

Hideo Okamoto

Atsushi Iwasaki

Toshiharu Uesugi

Kenji Araki

Tetsuhiro Oda

A method of producing a single crystal by Czochralski method by contacting a seed crystal with a melt in a crucible, and then pulling it slowly to grow a single crystal ingot, wherein a pulling condition is controlled according to a cumulative time of use of a heater surrounding the crucible. The pulling conditions to be controlled may induce the relative position of the heater and the crucible, the number of rotations of the crucible, the number of rotations of the crystal, or an atmosphere pressure in the furnace and a gas volume of flowing. Also described is a method of producing a silicon single crystal by CZ method wherein a dispersion of impurity concentration in the crystal can be reduced, and a single crystal can be produced stably.

Method for producing a silicon single crystal

A method and a mechanism for lifting a gas flow-guide cylinder of a crystal pulling apparatus are disclosed. The crystal pulling apparatus includes a crucible for accommodating a crystalline material and for melting the crystalline material through heating, and a gas flow-guide cylinder capable of being moved upward/downward above the crucible. The crystal pulling apparatus is operated to grow a single crystal from the crystalline material by a pulling method. When a solid crystalline material is to be placed in the crucible, the gas flow-guide cylinder is moved upward to thereby separate the bottom end of the gas flow-guide cylinder away from the top portion of the crucible. This prevents the crystalline material from coming into contact with the gas flow-guide cylinder.

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Gunma-ken, Japan

Hideo Okamoto