| 摘要 |
PURPOSE:To provide a production device for a single crystal by a floating zone melting method which can form a GaAs single crystal of a large diameter having high purity, by providing an As-containing vessel controlled to a specific temp. in a vessel contg. a polycrystal of GaAs and a single crystal. CONSTITUTION:The GaAs polycrystal 6 in a quartz cylinder 1 is subjected to high-frequency induction heating to about 1,240 deg.C with a soaking coil 20 to make a melt part 5, and a seed crystal 3 is seeded therein. After necking, rotary support bars 10, 8 are moved downward to grow a single crystal 4. Then the temp. of the As 13 in an As-containing vessel 11 connected with a fine quartz tube 12 to the cylinder 1 in the above-mentioned method is controlled to the temp. at which the optimum pressure of arsenic satisfying the stoichiometric compsn. of the crystal is obtd. The above-mentioned temp. TA of the arsenic is determined as the value satisfying the equation [GGaAs is the temp. of the melt part 5; PGaAs is the vapor pressure of As in the melt part 5; PAs is the vapor pressure of As in the vessel 11 (determined clearly from the value of TAs)]. |
