Equipment and method for producing crystal by vertical boat method

Abstract

Equipment for crystal growth by a vertical boat method includes a crucible enclosing a raw material, an ampoule encapsulating the crucible, and a crystal growth heater provided around the ampoule to heat the raw material. The raw material is melted into a raw material melt by the crystal growth heater, and a temperature of the raw material melt is controlled such that a crystal grows in the crucible from a bottom toward a top thereof. The crucible encloses GaAs as the raw material and Si as a dopant. The ampoule includes an additional B2O3 as an additional raw material at a position separated from the raw material, and a B2O3 adding-heater to heat the additional B2O3 separately from the raw material. A temperature of the additional B2O3 is controlled by the B2O3 adding-heater during growth of the crystal such that at least a portion of the additional B2O3 is melted and supplied into the crucible.

Dependencies are inferred from the claim text.