QUARTZ GLASS CRUCIBLE AND MANUFACTURING METHOD THEREOF
First Claim
1. A quartz glass crucible for pulling up a silicon single crystal, comprising:
- a high-aluminum-content layer which is made of quartz glass having a relatively high average aluminum concentration and is provided to form an outer surface of the quartz glass crucible; and
a low-aluminum-content layer which is made of quartz glass having a lower average aluminum concentration than that in the high-aluminum-content layer and is provided on an inner side of the high-aluminum-content layer,wherein the low-aluminum-content layer includes an opaque layer made of quartz glass containing a large number of minute bubbles, andthe high-aluminum-content layer is made of transparent or translucent quartz glass having a lower bubble content than does the opaque layer.
1 Assignment
0 Petitions
Accused Products
Abstract
In an exemplary embodiment, a quartz glass crucible 1 includes: a high-aluminum-content layer 14B which is made of quartz glass having a relatively high average aluminum concentration and is provided to form an outer surface 10b of the quartz glass crucible 1; and a low-aluminum-content layer 14A which is made of quartz glass having a lower average aluminum concentration than that of the high-aluminum-content layer 14B and is provided on an inner side of the high-aluminum-content layer 14B, wherein the low-aluminum-content layer 14A includes an opaque layer 11 made of quartz glass containing a large number of minute bubbles, and the high-aluminum-content layer 14B is made of transparent or translucent quartz glass having a lower bubble content than that of the opaque layer 11. The quartz glass crucible is capable of withstanding a single crystal pull-up step undertaken for a very long period of time.
1 Citation
20 Claims
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1. A quartz glass crucible for pulling up a silicon single crystal, comprising:
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a high-aluminum-content layer which is made of quartz glass having a relatively high average aluminum concentration and is provided to form an outer surface of the quartz glass crucible; and a low-aluminum-content layer which is made of quartz glass having a lower average aluminum concentration than that in the high-aluminum-content layer and is provided on an inner side of the high-aluminum-content layer, wherein the low-aluminum-content layer includes an opaque layer made of quartz glass containing a large number of minute bubbles, and the high-aluminum-content layer is made of transparent or translucent quartz glass having a lower bubble content than does the opaque layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A manufacturing method of a quartz glass crucible according to a rotating mold method, the manufacturing method comprising:
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a step of forming a deposition layer of raw material quartz powder by depositing aluminum-added quartz powder and natural quartz powder in this order on an inner surface of a rotating mold; and a step of subjecting the deposition layer of the raw material quartz powder to arc melting from an inner side of the mold, wherein the step of subjecting the deposition layer of the raw material quartz powder to the arc melting includes a step of forming an inner transparent layer made of quartz glass with substantially no bubbles contained therein by strengthening a degree of decompression through a large number of vent holes provided in the inner surface of the mold at the time of start of the arc melting, a step of forming an opaque layer made of quartz glass containing a large number of minute bubbles by weakening the degree of decompression after forming the inner transparent layer, and a step of forming an outer transparent layer made of quartz glass with substantially no bubbles contained therein by strengthening the degree of decompression again after forming the opaque layer, and in the step of forming the outer transparent layer, the high-aluminum-content layer is formed by melting the aluminum-added quartz powder, and a timing at which the degree of decompression is strengthened again is controlled to form the outer transparent layer so as to cause a thickness of the outer transparent layer to be thicker than that of the high-aluminum-content layer. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification