Shin-etsu Quartz Products Co., Ltd.

Yuji Baba

A quartz glass crucible including a bottom portion, a curved portion, and a straight body portion, where the quartz glass crucible includes an outer layer including opaque quartz glass containing bubbles therein, and an inner layer including transparent quartz glass, the outer layer includes a plurality of layers in a part of the straight body portion, out of the plurality of layers, one layer having a devitrification spot number of 50/cmor more and 70/cmor less when the quartz glass crucible is heated at 1600&#xb0; C. for 24 hours, and a layer positioned inwards of the devitrifiable layer in a thickness direction of the quartz glass crucible is a low devitrification layer having a spot number of 2/cmor less when the quartz glass crucible is heated at 1600&#xb0; C. for 24 hours. This provides a quartz glass crucible suppressed from deformation due to heating and excessive progression of devitrification.

Quartz glass crucible

A quartz glass crucible including bottom, curved, and straight body portions, where the quartz glass crucible includes an outer layer including opaque quartz glass containing bubbles, and an inner layer including transparent quartz glass, the outer layer fabricated from different types of raw material powder, the outer layer having regions sectioned by bubble content densities, and bubble content densities of two outer layer adjacent regions, when d(pcs/mm) is defined as content density of a region 'a' having a greater content density, and d(pcs/mm) is defined as content density of a region 'b' having a smaller content density, a difference D=(d&#x2212;d)/dbetween content densities of the two regions is 10% or more.

Quartz glass crucible and method for producing the same

The present invention is a method for producing a quartz glass crucible for pulling a single crystal silicon from a silicon melt held therein, including the steps of: producing a quartz glass crucible having an outer layer including an opaque quartz glass containing bubbles therein and an inner layer including a transparent quartz glass containing substantially no bubbles; roughening a region of an inner surface of the produced quartz glass crucible, the region being in contact with the silicon melt when holding the silicon melt; and heating the quartz glass crucible having the roughened inner surface to crystallize a surface of the roughened region. This can produce a quartz glass crucible for pulling a single crystal silicon which can suppress generation of a brown ring on the inner surface of the crucible during pulling the single crystal silicon and can suppress crystallinity disorder of the single crystal silicon.

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Takefu, Japan

Yuji Baba