Quartz glass crucible, process for producing the same, and use

Abstract

A crucible has a structure where a layer containing a crystallization accelerating component such as aluminum or the like (a crystallization accelerating layer) is inserted inside a quartz glass layer of a crucible straight body part excepting a crucible bottom part. The crucible does not deform and fall inwardly at the straight body part since a part containing a crystallization accelerating component advances to crystallize so as to increase strength at a high temperature when the crucible is used in pulling up silicon single crystal. Therefore, a single crystallization rate can be increased. Further, since the crystallization accelerating layer is inserted inside the quartz glass layer, the crystallization accelerating component, such as aluminum or barium, does not contact with silicon melt or a carbon susceptor, contamination by eluting these metals does not occurs. Further, since the crystallization accelerating layer is not provided at the crucible bottom part, there is no danger to crack due to thermal distortion at a time of pulling up silicon single crystal and melt leakage does not occur.

Description

technical field [0001] The present invention relates to a quartz glass crucible, particularly a quartz glass crucible used in pulling a silicon single crystal, and more particularly, to a high-temperature application of pulling a silicon single crystal, which has excellent mechanical strength and almost no dislocations at the initial stage of pulling Quartz glass crucibles that occur and have a high rate of single crystal crystallization. Background technique [0002] Quartz glass crucibles are generally used for pulling silicon single crystals. In order to increase the yield of silicon single crystal, many improvements have been made to this quartz glass crucible. For example, the most commonly used quartz glass crucible is a crucible with a double structure in which the inner surface of the crucible is formed by a transparent quartz glass layer substantially free of bubbles, and the outer surface side is formed by an opaque quartz glass layer containing more bubbles (refe...

AI Technical Summary

Problems solved by technology

However, it is conventionally known that a layer containing a crystallization accelerator is provided in the entire crucible from the straight part of the crucible to the bottom, and this layer contains the crystallization accelerator, so the thermal expansion coefficients of the outer and inner layers of the crucible on both sides are different, If the layer containing the crystallization accelerator is placed all the way to the bottom of the crucible, since molten silicon remains at the bottom of the crucible, cracks will be generated on the bottom of the crucible due to thermal strain at the end of the crucible's use, causing a problem of liquid leakage

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