Abstract:
A gallium arsenide crystal is produced by introducing a mixture of gallium hydride and arsenic chloride and/or arsenic hydride into the region surrounding a gallium arsenide crystal substrate heated to a temperature above the pyrolitic disintegration temperature of the mixture, whereby pyrolitic disintegration of the mixture takes place and a gallium arsenide crystal is grown epitaxially on the substrate. The gallium and arsenic compounds may be in the gaseous or liquid form. Hydrogen may be included in the mixture. A GaAs wafer 4, placed on graphite block 2 coated with thin quartz layer 3 situated inside quartz reaction chamber 1, is heated to 600 DEG C. by induction windings 5. A gas mixture comprising H2, Ga2H6, AsCl3 or H2, Ga2H6, AsH3 at 20 DEG C. is passed over the GaAs wafer through 6 and 7. Effluent gas mixture flows out through 8, and may be directed into an additional reaction chamber. By including suitable doping material in the gas mixture, PN junction may be produced on a seed doped with P-type impurities. The growth of the epitaxial layer may be limited to certain areas determined by a thermal mask.