Abstract: In a single crystal growing technique (crystal pulling) a method for minimizing impurity contamination and preventing heat convection currents from affecting the solid-melt crystal growing interface which uses a floating baffle plate in the interior of the feed melt containing crucible in order to obtain a single crystal of a compound semiconductor having a high melting point and exhibiting a high dissociation pressure at said melting point such as a compound semiconductor of Groups III-V, especially GaAs or Gap, the crystal having a small dislocation density. Improvement is made on the shape of the baffle plate and on baffle plate control mechanisms, and this baffle plate is combined with selected intra-furnace pressure or heating mechanisms or temperature measuring mechanisms.

Abstract: In a single crystal growing technique (crystal pulling) a method and apparatus for minimizing impurity contamination and preventing heat convection currents from affecting the solid-melt crystal growing interface which uses a floating baffle plate in the interior of the feed melt containing crucible in order to obtain a single crystal of a compound semiconductor having a high melting point and exhibiting a high dissociation pressure at the said melting point such as a compound semiconductor of Groups III-V, especially GaAs or Gap, the crystal having a small dislocation density. Improvement is made on the shape of the baffle plate and on baffle plate control means, and this baffle plate is combined with selected intra-furnace pressure or heating means or temperature measuring means.

Abstract: In pulling a single crystal of a compound semiconductor having a high melting point and exhibiting a high dissociation pressure at such melting point, like a compound semiconductor of elements of Groups III-V such as GaAs or GaP, from a feed melt contained in a crucible and subject to an inert gas atmosphere of a high pressure, apparatus for positioning a baffle plate floating in the feed melt in a predetermined position in a stable state in order to prevent heat convection of the feed melt in the crucible from affecting the solid-melt interface and consequently a single crystal having a small dislocation density can be obtained.

Abstract: In a high pressure vessel such as an electric furnace using an inert gas of an extremely high pressure as an atmosphere for preventing the evaporation of arsenic or phosphorus when pulling a single crystal of a compound semiconductor having a high melting point and exhibiting a high dissociation pressure at the melting point, such as a III-V Group compound semiconductor, e.g. GaAs or GaP from a feed melt contained in a crucible, it is intended to rotate and vertically move a crucible supporting shaft and a single crystal pulling shaft smoothly without impairing at all the gas-tightness in the furnace, the drive means utilizing a magnetic force for performing such rotational and vertical movements.