| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vitreous silica crucible which can restrain deterioration of crystallinity of a silicon ingot even in multi-pulling. <P>SOLUTION: The vitreous silica crucible 1 used for pulling a silicon single crystal has a wall having, from an inner surface toward an outer surface of the crucible 1, a synthetic vitreous silica layer, a natural vitreous silica layer, an impurity-containing vitreous silica layer, and a natural vitreous silica layer. The thickness of the impurity-containing layer at the bottom portion 33 of the crucible 1 is thinner than that at the sidewall portion 31 of the crucible 1, or the impurity-containing layer 3c is not formed at the bottom portion 33 of the crucible 1. The thicknesses of the impurity-containing layer at the sidewall portion 31 and the corner portion 32 of the crucible 1 are 30 to 70% of the thickness of the crucible 1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
