Quartz glass crucible for silicon single crystal pulling operation and process for manufacturing the same
AssigneesHeraeus Quarzglas GmbH & Co. KG, Shin-Etsu Quartz Products Co., Ltd.
InventorYasuo Ohama
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Abstract
A quartz glass crucible for silicon single crystal pulling operation that by a simple arrangement, attains prevention of any collapse onto the inside at a superior edge of straight trunk part; and a process for manufacturing the same. The quartz glass crucible for silicon single crystal pulling operation having a straight trunk part and a bottom part, is characterized in that at least the straight trunk part is provided with a gradient of fictive temperature so that the fictive temperature on the outermost side thereof is 25° C. or more lower than the fictive temperature on the innermost side thereof.
Claims9
A quartz glass crucible for pulling a silicon single crystal, said quartz glass crucible comprising a straight body part and a bottom part, wherein the straight body part has a fictive temperature gradient wherein an innermost fictive temperature is set between 1185° C. and 1265° C., and an outermost fictive temperate is set between 1145° C. and 1210° C. respectively, and the outermost fictive temperature is at least 25° C. lower than the innermost fictive temperature.
A method of producing a quartz glass crucible for pulling a silicon single crystal, said method comprising:
- fusing the crucible, then lowering an outside fictive temperature of the crucible by holding the crucible inside a mold and maintaining a temperature of the outside of the crucible for a prescribed period of time so as to form a fictive temperature gradient on at least a straight body part of the crucible, wherein an innermost fictive temperature is set between 1185° C. and 1265° C., and an outermost fictive temperature is set between 1145° C. and 1210° C. respectively, and the outermost fictive temperature of the straight both part is at least 25° C. lower than the innermost fictive temperature thereof.
Dependencies are inferred from the claim text.