| 摘要 |
PURPOSE:To improve the purity of silicon by blasting a plasma jet stream of an inert gas added with a specific amount of steam and/or SiO2 to the surface of molten Si held in a vessel made of SiO2 or an SiO2 mixture. CONSTITUTION:Si is put into a crucible 11 covered with a heat-insulation lining 3, having a hole on the bottom and made of SiO2 or a material composed mainly of SiO2. The Si is melted by heating with a dielectric heating coil 4. A plasma jet stream 10 of an inert gas such as Ar added with 0.1-10vol.% of steam and/or <=1g of SiO2 (based on 1NL of the inert gas) is blasted together with an electron beam 12 from a plasma arc torch 5 against the molten Si 1. The molten Si 1 is stirred by the action of the plasma jet 10 and the electron beam 12 to promote the elimination reaction of B and C in the molten Si 1 from the high- temperature part and obtain a high-purity Si. |
