High purity silicon prodn. - by reaction of high purity halo:silane and hydrogen in a continuous flow reactor

摘要

High purity Si is made by (a) pre-heating an H2 stream to 900 degrees - 1200 degrees C; (b) pre-heating a halosilane stream to 900 degrees - 1200 degrees C; (c) feeding each stream separately to a mixing chamber to form a continuous reaction stream producing Si; (d) feeding a high velocity stream of Si particle seeds pre-heated to 900 degrees - 1200 degrees C into the mixer; and (e) recovering the si prod. from the vapour stream. Prefd. halosilanes are SiBHr3 and SiBr4. Used in semiconductor devices. Method is energy-efficient and reactor effluents may be recovered and recycled, the only raw material being low-cost metallurigal grade Si.