| 摘要 |
<p>There is provided a vitreous silica crucible whose strength at high temperature is high, and which allows easy taking-out from a susceptor after completion of pulling. The vitreous silica crucible 10 includes a vitreous silica outer layer 13a provided on the outer surface side of the crucible, a vitreous silica inner layer 13c provided on the inner surface side of the crucible, and an vitreous silica intermediate layer 13b provided between the vitreous silica outer layer 13a and the vitreous silica inner layer 13c. The vitreous silica outer layer 13a has a mineralizer concentration of 100 ppm or more, and the vitreous silica intermediate layer 13b and the vitreous silica inner layer 13c has a mineralizer concentration of 50 ppm or less. It is preferred that the vitreous silica outer layer 13a and the vitreous silica intermediate layer 13b are made of natural silica, and the vitreous silica inner layer 13c is made of high-purity natural silica or synthetic silica. The thickness of the vitreous silica outer layer 13a is 0.5 mm to 2.0 mm on the bottom portion 10B, and the thickness on the sidewall portion 10A of the vitreous silica outer layer 13a is larger than that on the bottom portion 10B.</p> |
