Self-clamping holder for polysilicon rod used in floating-zone single-crystal growth method

摘要

A self-clamping holder (22) capable of holding a polysilicon rod (P) using the weight of the polysilicon rod is disclosed. The holder includes a generally cup-shaped adapter (24) having an open end facing downward, and at least three clamp jaws (34) rotatably mounted on the adapter adjacent to the open end and circumferentially spaced at equal angular intervals for clamping or gripping an end of the polysilicon rod received in the adapter (24). The clamp jaws have arcuate cam surfaces (36) disposed interiorly of the adapter and profiled such that a radius of curvature of the cam surfaces gradually increases as the clamp jaws turn in a downward direction of the adapter. With this construction, the polysilicon rod is firmly gripped by the clamp jaws (34) against detachment from the holder. The clamp jaws produces a clamping force acting on the peripheral surface of the polysilicon rod and distributed uniformly in the circumferential direction of the polysilicon rod. With this clamping force, the polysilicon rod is held in a vertical position so that a longitudinal central axis of the polysilicon rod is aligned with an axis of rotation of the adapter while the polysilicon rod is rotating.