Japan Super Quartz Corporation

Sumco Corporation

Masaru Sato

Toshiaki Sudo

Ken Kitahara

Masaki Morikawa

Takuma Yoshioka

Masami Ohara

A silica glass crucible includes a cylindrical side wall portion, a curved bottom portion, and a corner portion that is provided between the side wall portion and the bottom portion and has a higher curvature than a curvature of the bottom portion, in which a first region provided from a crucible inner surface to a middle in a thickness direction, a second region that is provided outside the first region in the thickness direction and has a different strain distribution from the first region, and a third region that is provided outside the second region in the thickness direction and up to the crucible outer surface and has a different strain distribution from the second region, are provided, and internal residual stresses of the first region and the third region are compressive stresses, whereas an internal residual stress of the second region includes a tensile stress.

Silica glass crucible

A cutting method and an apparatus are provided which enable a rim area or other part of a vitreous silica crucible to be cut off so as to leave a smooth cut surface without damaging the cut edge, etc. The apparatus for cutting the crucible comprises a disk-shaped cutting blade () disposed to be movable with respect to the crucible. Without rotating the crucible (), the rotating cutting blade () is brought into contact with a surface of the crucible wall and pushed forward in the wall thickness direction to make a cut piercing the crucible wall. The cutting blade () is moved relatively to the crucible () in the circumferential direction of the crucible () while keeping the cutting blade in the state of piercing the wall. A rim area () of the crucible () is thus cut off.

Apparatus for cutting vitreous silica crucible

A closure for silica glass crucible to be mounted on an opening portion of a silica glass crucible is provided with a peripheral edge mounting portion closely adhered to an inner peripheral end of the opening portion.

Closure for silica glass crucible, silica glass crucible and method of handling the same

A vitreous silica crucible has high strength at high temperature, and allows easy taking-out from a susceptor after completion of pulling. The vitreous silica crucible includes a vitreous silica outer layer provided on the outer surface side of the crucible, a vitreous silica inner layer provided on the inner surface side of the crucible, and an vitreous silica intermediate layer provided between the vitreous silica outer layer and the vitreous silica inner layer. The vitreous silica outer layer has a mineralizer concentration of 100 ppm or more, and the vitreous silica intermediate layer and the vitreous silica inner layer has a mineralizer concentration of 50 ppm or less. The thickness of the vitreous silica outer layer is 0.5 mm to 2.0 mm on the bottom portion, and the thickness on the sidewall portion of the vitreous silica outer layer is larger than that on the bottom portion.

Vitreous silica crucible having outer, intermediate, and inner layers

A crucible for pulling a silicon single crystal has a double structure comprising a silica crucible and a graphite crucible covering an outside of the silica crucible, wherein the silica crucible is provided at its opening end portion with an inward falling prevention means for imparting a radially outward force to a body portion of the silica crucible.

Crucible and method for pulling a single crystal

In an apparatus for the production of a silica crucible comprising a carbon mold suitable for producing the silica crucible by the rotating mold method, the carbon mold has a thermal conductivity of not more than 125 W/(m&#xb7;K).

Growing community of inventors

Akita, Japan

Masaru Sato