| 摘要 |
PROBLEM TO BE SOLVED: To improve efficiency of a silicon purifying process of the latter method and to better the yield of a product, by equipping a melting part with a filter and filtering a molten silicon to effectively remove intervening impurities in electron beam melting in purifying silicon by the electron beam melting. SOLUTION: A raw material silicon 3 is supplied to a hearth 1 and melted by electron beam. A filter 4 is installed in the hearth 1 and intervening impurities 5 are caught. The intervening impurities are caught by the filter 4 and a molten silicon 2 is passed through the filter. A sintered filter of high purity SiC is used as the filter 4 and a material which is stable at a high temperature in high vacuum and has a small amount melted into silicon is proper. For example, carbon and silicon carbide are suitable due to stability at high temperature in high vacuum, a small amount melted into molten silicon of about 100ppm and ready oxidation and removal. |
