| 摘要 |
PURPOSE:In a crucible, a group V element substance is dissolved in a group IIIelement substance then, a temperature gradient is applied to the resultant solution and a direct current is applied thereto from the bottom toward the top to promote the growing speed of the titled crystals. CONSTITUTION:High-purity gallium 12 and arsenic 20 are placed in prescribed places and the quartz tube 11 is evacuated and sealed. The sealed tube 11 is heated with heaters 21 and 22 to keep the arsenic at about 500-600 deg.C, while the graphite crucible containing gallium 12 is set in the zone where a temperature ingredient is formed so that the melt surface of gallium is about 920 deg.C and the bottom of the crucible is about 880 deg.C. Further a direct current is allowed to flow in the melt 12 from the anode of the crucible bottom 13 to the cathode of the graphite cylinder 17. At this state, the arsenic sublimes, as it is keeping a prescribing vapor pressure according to the temperature of the quartz tube bottom, and reaches the surface of the solution 12, then dissolves in it, moves to the low- temperature zone by the electromigration and diffusion caused by the temperature ingredient and precipitates out as semiconductor crystals of Ga-As. |
