Carbon electrode and equipment for manufacturing polycrystalline silicon rod

摘要

Provided is a highly effective technique for preventing the occurrence of cracking and breaking of a U-shaped rod that can expand and contract in every direction during vapor-phase deposition of a polycrystalline silicon rod. A fixing portion of a core holder (20) for holding a silicon core (5a) is provided on the upper surface side of the upper electrode (31) of a carbon electrode (30). On the upper electrode (31), an opening (through-hole) (35) penetrating from the upper surface (33) to the lower surface (34) is provided, and a bolt (36) that is a rod-like fastening member is inserted through a washer (37) from the upper surface (33) of the upper electrode (31) into the opening (35) and is fastened to a lower electrode (32) by screwing. A space (51) around the straight body portion of the bolt (36) in the opening (35) enables the upper electrode (31) to slide in every direction within the area of a placement surface that is the contact surface between the upper electrode (31) and the upper surface of the lower electrode (32) and, in FIG. 2, corresponds to the upper surface of the lower electrode (32), which contacts the lower surface (34) of the upper electrode (31). As a result, the occurrence of cracking and breaking of a U-shaped rod that can expand and contract in every direction during vapor-phase deposition can be effectively prevented.