| 摘要 |
PURPOSE:To produce a GaAs single crystal having high uniformity and quality with good reproducibility, by applying a magnetic field corresponding to a specific region having small thermal vibration of a raw material melt and wide proper range of application intensity of the magnetic field, controlling the internal pressure of a furnace within a specific range and pulling up the aimed GaAs single crystal. CONSTITUTION:GaAs raw materials are put in a crucible 62 and a B2O3 encapsulating agent is placed thereon. The interior of a vessel 61 is replaced with an Ar gas atmosphere and the crucible 62 is heated by a heater 64 in a pressurized state to position a liquid encapsulation layer 82 on the GaAs raw material melt 81. The interior of the vessel 61 is set at 5-15atm and a magnetic field is applied in the horizontal direction with superconductive magnets 71 and 72 to adjust the magnetic field intensity in the melt 81 to about 3,500, namely condition is set so that the carbon concentration may be <=1X10<16>atms/cm<3> in the pulled up crystal in the fourth region having small thermal vibration of the raw material melt and the concentration difference between the head and tail parts may be the minimum. In this state, a seed crystal 83 is brought into contact with the melt 81 to pull up and produce the aimed GaAs single crystal. Thereby the GaAs single crystal having extremely high uniformity and good quality can be produced with good reproducibility.
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