| 摘要 |
An apparatus for growing a single crystal of GaAs, comprising an ampoule having a closed upper end, a boat surrounded by the ampoule and directly bonded to an upper portion of the ampoule at its upper portion where no GaAs melt is present, without using any support member. The boat includes a cylindrical boat body, a conical shoulder extending downwardly from a lower end of the boat body, and a cylindrical seed well extending downwardly from the shoulder and having a closed lower end, the seed well having a diameter smaller than than of the boat body and containing a seed crystal therein. Upon forming the single crystal of GaAs according to the vertical-gradient freeze method, the heat flow at the boat body and shoulder of boat can be uniform to prevent a local heat flow transition, thereby capable of restraining formations of a polycrystal and a twin and thus forming a GaAs single crystal being homogeneous at all portions from its seed portion to its tail portion. |
