QUARTZ GLASS CRUCIBLE SUPPRESSED IN THERMAL EXPANSION, AND METHOD OF PULLING SILICON SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To provide a quartz glass crucible which is little in thermal expansion in single crystal pulling and makes it possible to obtain a high single crystal yield.;SOLUTION: The quartz glass crucible used for pulling silicon single crystals, is characterised in that the thermal expansion under standard heating conditions of any part of the crucible is 8% or smaller, and the mutual thermal expansion difference among respective parts of the crucible is 5.5% or smaller, and also it is characterised by suppressing the thermal expansion of respective parts of it, for example when it is manufactured by heating and melting a quartz powder, by such a manner that the quartz powder is heated at a temperature of 1,800°C or higher for 5 min or longer to be vitrified, the bubble containing ratios in all wall thickness directions of it are adjusted in the range of 0.05% to 0.4%, or helium gas, hydrogen gas, or steam is introduced and at the same time, the bubble containing ratios in the all wall thickness directions of it are adjusted in the range of 0.05% to 0.8% in the above-mentioned melt-vitrification.;COPYRIGHT: (C)2006,JPO&NCIPI