| 摘要 |
PURPOSE:To prepare the titled single crystal having high purity, low degree of defect, and high heat stability by performing crystal growth by the pulling method while restricting the range of temp. variation to below a specified value of the range by impressing magnetic field to the melt of GaAs contg. low concn. of Cr. CONSTITUTION:Starting materials and a sealing material in a crucible 3 provided in a high-pressure vessel 1 are melted, and a layer 6 of molten B2O3 is formed in the upper layer and a layer of melt 5 of GaAs is formed in the bottom of the crucible. A pulling rod 8 is moved downward, and when a seed crystal 7 is brought into contact with the melt layer 5, magnetic field is impressed by a magnetic field impressing apparatus 11 is applied to the melt layer 5. In this case, the intensity of the magnetic field to be impressed is regulated to a value by which the convection of heat is retarded and the range of variation of temp. near the boundary surface of the melt is regulated to <=1 deg.C. GaAs single crystal 10 is grown by pulling up the seed crystal 7 by rotating it at a specified rotational speed while maintaining the above described temperature variation range. |
