SYSTEM FOR PRODUCING POLYCRYSTALLINE SILICON, APPARATUS FOR PRODUCING POLYCRYSTALLINE SILICON, AND METHOD FOR PRODUCING POLYCRYSTALLINE SILICON

摘要

PPROBLEM TO BE SOLVED: To provide a technology producing high purity polycrystalline silicon by effectively recovering heat from a coolant used for cooling a reaction furnace and by decreasing mixing of dopant impurities from an inner wall of the reaction furnace upon precipitating polycrystalline silicon in the reaction furnace. PSOLUTION: In a system for producing high purity polycrystalline silicon, hot water 15 having the temperature higher than the standard boiling point is used as a coolant to be supplied to a reaction furnace 10, so as to keep the inner wall temperature of a reactor at 370C or lower and the hot water 15 is evacuated by a pressure control unit provided in a coolant tank 20 to generate steam and a part of the steam is taken out so as to reuse as a heating source for another purpose. An alloy material of a composition having an R value of 40% or more, which is defined by R=[Cr]+[Ni]-1.5[Si], is used as a material for a corrosion-resistant layer 11a provided in the inner side of the inner wall of the reaction furnace 10. PCOPYRIGHT: (C)2011,JPO&INPIT