METHOD FOR CONTINUAL PREPARATION OF POLYCRYSTALLINE SILICON USING A FLUIDIZED BED REACTOR

摘要

There is provided a method for continual preparation of granular polycrys talline silicon using a fluidized bed reactor, enabling a stable, long-term operation of the reactor by effective removal of silicon deposit accumulated on the inner wall of the reactor tube. The method comprises (i) a silicon p article preparation step, wherein silicon deposition occurs on the surface o f the silicon particles, while silicon deposit is accumulated on the inner w all of the reactor tube encompassing the reaction zone; (ii) a silicon parti cle partial discharging step, wherein a part of the silicon particles remain ing inside the reactor tube is discharged out of the fluidized bed reactor s o that the height of the bed of the silicon particles does not exceed the he ight of the reaction gas outlet; and (iii) a silicon deposit removal step, w herein the silicon deposit is removed by supplying an etching gas into the r eaction zone.