| 摘要 |
PURPOSE:To produce a single crystal having low dislocation density, in high reproducibility, by adding a specific amount of In to the polycrystalline raw material in the production of a GaAs single crystal by liquid encapsulated pulling method. CONSTITUTION:1,000g of a polycrystalline GaAs is doped with 360-36,000mg of InAs, and used as a raw material for the liquid encapsulated pulling method. Since InAs having lower decomposition pressure than GaAs is added to the raw material, the vacancies of As are decreased by the growth of the crystal from the molten liquid containing As in excess, and the number of complex defects of the As vacancy and other impurities is decreased resulting in the lowering of the dislocation density. A single crystal having excellent characteristics can be produced by carrying out the above process keeping the furnace pressure at about <=30kg/cm<2> and pulling rate at 3-20mm./hr. The process is effective for the production of a GaAs single crystal having a diameter of about >=50mm. on an industrial scale. |
