| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing purified silicon by cutting off a crude silicon region, without determining the aluminum concentration in a directionally-solidified product of silicon. SOLUTION: In the method, a standard solidification fraction f<SB>0</SB>satisfying the following formula (1) is obtained from the predetermined maximum level of aluminum concentration C<SB>10max</SB>, the temperature gradient T and the solidification speed R, and the directionally-solidified product 4 of silicon is cut at the part having a solidification fraction f in the solidification step corresponding to f<SB>0</SB>. The formula (1) is k=äK<SB>1</SB>×Ln(R)+K<SB>2</SB>}×äK<SB>3</SB>×exp[K<SB>4</SB>×R×(K<SB>5</SB>×C<SB>2</SB>+K<SB>6</SB>)]}×äK<SB>7</SB>×T+K<SB>8</SB>}-K<SB>9</SB>, wherein k is a coefficient selected from a range of 0.9 times to 1.1 times the effective aluminum partitioning coefficient k', obtained so as to satisfy the formula (2): C<SB>10max</SB>=k'×C<SB>2</SB>×(1-f<SB>0</SB>)<SP>k'-1</SP>(wherein, k' is effective aluminum partitioning coefficient; and C<SB>2</SB>is the aluminum concentration of the starting silicon melt). COPYRIGHT: (C)2009,JPO&INPIT
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