| 摘要 |
PROBLEM TO BE SOLVED: To provide a technology having a high suppression effect against generation of craze or crack on a U-rod extensible and contractable to every azimuth in a vapor-phase growth step of a polycrystalline silicon rod.SOLUTION: In a carbon electrode 30, an upper electrode 31 is placed on a lower electrode 32 in the state where a projection part provided on an upper part of the lower electrode 32 is inserted to the inside of a recessed part provided on a lower part of the upper electrode 31. The internal dimension of the recessed part 38 of the upper electrode 31 is larger than the external dimension of the projection part 39 of the lower electrode 32, and resultantly, a gap 52 is provided between the recessed part 38 and the projection part 39. The gap 52 between the recessed part 38 and the projection part 39 enables the upper electrode 31 to perform omnidirectional in-plane slide on the placing surface which is a contact surface with the upper surface of the lower electrode 32, to thereby show a suppression effect to generation of craze or crack on a U-rod extensible to every azimuth in a vapor-phase growth step. |
