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US 8,506,708 B2Granted
Silica glass crucible for pulling up silicon single crystal, method for manufacturing thereof and method for manufacturing silicon single crystal
AssigneeJapan Super Quartz Corporation
InventorsMasanori Fukui, Satoshi Kudo
Life of this patent
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Abstract
A silica glass crucible for pulling up a silicon single crystal including a wall part and a bottom part is provided with a natural silica glass layer which forms at least one part of a an inner surface of the bottom part, and a synthetic silica glass layer which forms at least an inner surface of the wall part, wherein a concentration of Ca included in the natural silica glass layer is 0.5 ppm or less.
Claims5
A silica glass crucible for pulling up a silicon single crystal including a wall part and a bottom part comprising:
- a first natural silica glass layer which forms at an outer layer in the wall part and the bottom part;
- a synthetic silica glass layer which forms an inner layer in the wall part and the bottom part, and which is exposed in at least the wall part;
- and
- a second natural silica glass layer which covers a region which includes the center of the bottom part among the inner surfaces of the synthetic silica glass layer;
- wherein
- a concentration of Ca included in the second natural silica glass layer is 0.5 ppm or less, and a thickness of the second natural silica glass layer is 30 μm or more and 200 μm or less.
3 more elements
Dependencies are inferred from the claim text.