Patent ID: 8658118
Filing Date: 2014-02-25
Classification: C01B,C30B,Y10T

Abstract:
1. A production process for high purity crystalline silicon, which is a process for producing a high purity crystalline silicon having a boron content of 0.015 ppmw or less and a zinc content of 50 to 1000 ppbw, comprising: (1) a step in which in a vertical reactor equipped with a silicon tetrachloride gas-supplying nozzle, a zinc gas-supplying nozzle and a waste gas-discharging pipe, the silicon tetrachloride gas-supplying nozzle being inserted into an inside of the reactor from an upper part thereof and set therein, a silicon tetrachloride gas is supplied from the silicon tetrachloride gas-supplying nozzle and a zinc gas is supplied from the zinc gas-supplying nozzle, (2) a step in which the silicon tetrachloride gas is reacted with the zinc gas at 800 to 1200° C. to thereby form crude crystalline silicon at a chip part of the silicon tetrachloride gas-supplying nozzle, (3) a step in which the crude crystalline silicon is grown downward from the chip part of the silicon tetrachloride gas-supplying nozzle, (4) a step in which the grown crude crystalline silicon is discharged to an outside of the vertical reactor and (5) a step in which the discharged crude crystalline silicon is subjected to acid treatment, wherein high purity silicon tetrachloride having an organic silicon compound content of 0.1 ppmw or less and a boron content of 0.1 ppbw or less is used as a raw material of the silicon tetrachloride gas, and metal zinc having a purity of 99.99% by weight or more is used as a raw material of the zinc gas.