Shin-etsu Quartz Products Co., Ltd.

Heraeus Quarzglas Gmbh & Co Kg

Shin-etsu Handotai Co., Ltd.

Heraeus Quarzglas Gmbh

Hiroshi Matsui

Mitsuo Matsumura

Akira Fujinoki

Atsushi Iwasaki

Yasuo Ohama

Yasuhiko Sato

Nobuyoshi Ogino

Masaaki Aoyama

Eiichi Shinomiya

Akira Uchikawa

Toshio Fukuoka

Tatsuhiro Sato

Hiroyuki Watanabe

Rainer Koeppler

Tsukasa Sakaguchi

Fritz-Ulrich Kreis

Klaus Arnold

Kasumi Hoshikawa

The present invention refers to a method for producing a quartz glass crucible for use in pulling silicon single crystal, said crucible having at least a double-layer structure comprising a pore-free transparent inner layer and an opaque base body or outer layer having pores, characterized in that at least the base body is formed with a silica powder maintained in a gas having a mixing ratio of 0.0005 to 0.0065 kg/kg (dry gas), and a quartz glass crucible produced by said production method. The obtained crucible has an average OH group concentration of 50 ppm or lower and is capable of suppressing the vibration occurring on the surface of silicon melt during pulling the silicon single crystal. Further the obtained crucible suffers less deformation of the crucible on pulling the silicon single crystal.

Method for producing quartz glass crucible for use in pulling silicon single crystal and quartz glass crucible produced by said method

The granule consists of individual granules approximately spherical in shape, having a pore volume of 0.5 cm, a mean diameter of pores of 50 nm or less, a specific surface area of 100 m/g or less, and a bulk density of 0.7 g/cmor higher. It is produced by dispersing a fumed silica obtained by hydrolysis of a silicon compound into pure water to obtain a slurry, and drying the slurry. The granule is used for producing high purity synthetic quartz glass powder. The method further comprises: a first heat treatment under an oxygen-containing atmosphere, a second heat treatment in a temperature range of from 600 to 1100&#xb0; C., and a third heat treatment in a temperature range of from 1100 to 1300&#xb0; C. under an atmosphere containing hydrogen chloride; and a step of densification comprising calcining the product at a temperature not higher than 1500&#xb0; C. under vacuum or in an atmosphere of gaseous hydrogen or gaseous helium. To calcine the powder without causing fusion adhesion of the particles, bubbling fluidization of said porous silica granule is conducted by supplying gaseous helium and calcining thereof in a temperature range of from 1000 to 1600&#xb0; C.

Porous silica granule, method for producing the same, and method for producing synthetic quartz glass powder using the porous silica granule

Disclosed is a multilayer structured quartz glass crucible, for pulling up silicon single crystal, whose structure has at least three layers comprising: a translucent outer layer made of naturally occurring quartz glass and having a large number of pores, a translucent intermediate layer, made of synthetic quartz glass and having a large number of pores, and a transparent inner layer substantially free from pores and made of a synthetic quartz glass. Thermal convection within the silicon melt is suppressed by use of the quartz glass crucible, thereby preventing oscillation on the surface of the silicon melt. A method for producing the quartz glas crucible is also disclosed.

Multilayer structured quartz glass crucible and method for producing the same

Quartz powder is fed into a rotating mold to form a crucible-like quartz powder layer body with the help of centrifugal force in the mold. The layer is melted by heating through the inner surface with an arc discharge to manufacture an outer crucible member. A hollow cylindrical inner crucible member having a beveled lower edge is welded to the outer crucible member while a temperature of the inner surface portion of the outer crucible member remains at 1400.degree. C. or higher by a remaining heat.

Method of manufacturing crucible for double-crucible crystal growing

A quartz glass crucible for use in a process for pulling a single crystal silicon and having an outer layer and an inner layer. The outer layer contains less than 0.3 ppm each of Na, K and Li and more thant 5 ppm of Al. The outer layer further contains bubbles to present an opaque appearance. The inner layer is made by melting powders of high purity non-crystalline synthetic silica and contains less then 200 ppm of OH group. There is also disclosed a method for producing the crucible.

Manufacture of quartz glass crucible for use in the manufacture of

A quartz glass crucible adapted for use in a process for pulling a single crystal semiconductor material having an opaque outer substrate of a quartz glass with a relatively high bubble content and an inner transparent glass layer which is substantially free from bubbles. The crucible is produced while the substrate is supported by a rotating mould by forming an atmosphere of high temperature gas and supplying a metered quantity of powders of quartz to the high temperature gas atmosphere to have the quartz powders molten at least partly and directed toward an inner surface of the substrate to be adhered thereon.

Manufacture of a quartz glass vessel for the growth of single crystal

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Takefu, Japan

Hiroshi Matsui