| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for removing boron (B) and phosphorus (P) at the same time and easily and efficiently in purification of silicon. <P>SOLUTION: The method for purifying silicon is characterized in that silicon is brought into a molten state by heating the silicon containing impurities, a solid of either one or both of metallic calcium and calcium carbide as an additive for impurity purification, and a solid of calcium fluoride to the melting point of silicon and a slag is formed, and in that the impurities in the silicon are removed by making the impurities absorb into the slag. By using this method, a unidirectional solidification method and a vacuum melting method, metallic silicon can be purified into a high-purity silicon that is usable for a solar cell. Further, the obtained high-purity silicon can be utilized in various industries that require a high-purity silicon without being limited to the silicon raw material for a solar cell. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
