Invention Grant
- Patent Title: Vitreous silica crucible for pulling silicon single crystal
- Patent Title (中): 硅玻璃坩埚用于拉硅单晶
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Application No.: US12752374Application Date: 2010-04-01
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Publication No.: US08715415B2Publication Date: 2014-05-06
- Inventor: Makiko Kodama , Hiroshi Kishi , Minoru Kanda
- Applicant: Makiko Kodama , Hiroshi Kishi , Minoru Kanda
- Applicant Address: JP Akita
- Assignee: Japan Super Quartz Corporation
- Current Assignee: Japan Super Quartz Corporation
- Current Assignee Address: JP Akita
- Agency: Greenblum & Bernstein, P.L.C.
- Priority: JP2009-090518 20090402
- Main IPC: C30B15/10
- IPC: C30B15/10

Abstract:
Provided is a vitreous silica crucible for pulling silicon single crystals, which can melt a silicon raw material in a short time and improve production yield of silicon single crystals by temporal change of an opaque vitreous silica layer. The vitreous silica crucible includes an opaque vitreous silica layer(11) provided on an outer surface thereof and containing plural bubbles, and a transparent vitreous silica layer(12) provided on an inner surface and not containing bubbles substantially. The opaque vitreous silica layer(11) has a bubble diameter distribution in which the content of bubbles having a diameter of less than 40 μm is 10% or more and less than 30%, the content of bubbles having a diameter of 40 μm or more and less than 90 μm is 40% or more and less than 80%, and the content of bubbles having a diameter equal to or more than 90 μm is 10% or more and less than 30%. Relatively small bubbles contained in the opaque vitreous silica layer(11) contribute to the thermal conductivity of a crucible at an initial pulling stage, and relatively large bubbles contained in the opaque vitreous silica layer are expanded through a long-term pulling process to thereby largely contribute to the warmth retaining property of the crucible at a later pulling stage.
Public/Granted literature
- US20100251959A1 VITREOUS SILICA CRUCIBLE FOR PULLING SILICON SINGLE CRYSTAL Public/Granted day:2010-10-07
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