High-purity vitreous silica crucible used for pulling large-diameter single-crystal silicon ingot and manufacturing method

摘要

A high-purity vitreous silica crucible which has high strength and is used for pulling a Iarge-diameter single-crystal silicon ingot, includes a double laminated structure constituted by an outer layer composed of amorphous silica glass with a bubble content of 1 to 10% and a purity of 99.99% or higher and an inner layer composed of amorphous silica glass with a bubble content of 0.6% or less and a purity of 99.99% or higher, and in the portion between the upper opening end of the high-purity vitreous silica crucible and the ingot-pulling start line of a silicon melt surface in the step of pulling a single-crystal silicon ingot, a portion corresponding to 40 to 100 volume% from the upper opening end of the crucible is in a crystalline structure free from the crystallization promoter.A manufacturing method comprises adding a crystallization promoter to the silica raw material in a rim portion and cutting off the rim portion after part of the crucible has crystallized.