| 摘要 |
PURPOSE:In the liquid encapsulating method, the temperature gradient near the solid-liquid inter face in the starting melt for compound semiconductor is set higher outward in the radial direction in a certain temperature range to produce single crystals which causes no B-Pit and have less transition density of the wafer and less residual stress. CONSTITUTION:In the liquid encapsulating method, the starting materials for GaP crystals and B2O3 as a liquid encapsulating agent are melted in the quartz crucible 2 inside the pressure vessel 1 by heating with the carbon heater 3 to cover the surface of the GaP melt 4 with the B2O3 layer 5. The vessel has been previously filled with N2 gas by vacuum replacement and is pressurized, as the temperature is raised up, to avoid GaP from decomposing and vaporizing. Then, the seed crystal 6 is pulled up, as being rotated to form the GaP single crystal 7. At this time, the temperature gradient near the solid-liquid interface in the melt 4 is set higher outward in the radial direction in the range from 4 to 30 deg.C/cm within the zone of at least crossing the outer periphery 15 of the pulled-up crystal 13. |
