| 摘要 |
PURPOSE:To enable growth of a single crystal with excellent reproducibility, by improving a method for filling a raw material in a crucible, raw material synthesis, melting process, etc., in the direct synthetic vertical Bridgman process. CONSTITUTION:A diameter increasing part (1c) is provided between a cylindrical protruding part (1a) and constant diameter part (1b) of a crucible 1 and a seed crystal 2 is inserted into the protruding part (1a). A cap material layer 24 consisting of, e.g. previously synthesized or grown GaAs polycrystal or single crystal, is filled in the diameter increasing part (1c) or lower part of the constant diameter part (1b) or both. The cap material layer 24 is a solid and has action of suppressing contact of a seed crystal with a melt in the initial state. Metallic Ga 12 and metallic As 13 which are raw materials weighed at a required ratio are then filled in the upper part of the cap material layer 24 and an encapsulating agent 11, such as B2O3, etc., is subsequently filled. The raw materials are melted to synthesize a GaAs polycrystal 15, which is then melted together with the cap material layer 24. The resultant melt and seed crystal are grown into a single crystal having a desired orientation and shape.
|
