To provide a method for manufacturing silicon particles suitable for a solar battery, by which a high quality granular silicon single crystal in which the contamination with iron impurities is markedly reduced can be stably manufactured, and which is excellent in mass productivity and low in manufacturing cost.
The method for manufacturing the granular silicon single crystal comprises heating granular silicon in an atmosphere including a reactive gas so as to form a coating of a silicon compound containing the component of the gas on the surface of each granule and to melt silicon present inside, and then lowering temperature so as to solidify and crystalize. The iron concentration in the granular silicon single crystal is lowered to 35 ppm or less by subjecting the granular silicon to a heat treatment at 500-1,200°C in an atmospheric gas having an oxygen partial pressure of 10-100% for 10 min to 12 h after melting and solidifying the granular silicon.
KITAHARA NOBUYUKI
ARIMUNE HISAO
