| 摘要 |
PURPOSE:To economically prepare a long-sized core rod with extremely high efficiency within a short time, by connecting by welding a plurality of core rods each becoming a precipitation substrate in the axial direction to form a long semiconductive material. CONSTITUTION:A current is supplied to a high frequency heating coil 13 to heat a preheating ring 12 to a red heat state and, after core rods 5 are preheated by the heat of said ring 12, the high frequency heating coil 13 is raised to the abutted part of two core rods 5, 5' to melt the same under heating. Next, the abutted part is cooled to bond the core rods 5, 5' and the bonded core rods 5, 5' are taken out. Two polycrystalline silicon core rods 7X7mm square and respectively having lengths of 1,400mm, 1,000mm are welded by high frequency heating to prepare a long-sized core rod having a length of 2,400mm. 10 each of core rods thus prepared are assembled in a large-scale water cooling metal furnace and grown by a gaseous phase precipitation method to prepare 10 polycrystalline silicon rods each having a diameter of 67mm. |
