High-purity vitreous silica crucible for pulling large-diameter single-crystal silicon ingot
A high-purity vitreous silica crucible used for pulling a large-diameter single-crystal silicon ingot, includes a double layered structure constituted by an outer layer composed of high-purity amorphous vitreous silica with a bubble content of 1 to 10% and a purity of 99.99% or higher, and an inner layer composed of high-purity amorphous vitreous silica s with a bubble content of 0.6% or less and a purity of 99.99% or higher, wherein, at least for an inner surface of the vitreous silica crucible between ingot-pulling start line and ingot-pulling end line of a silicon melt surface, a longitudinal section of the inner surface is shaped into a waveform, and depth and width of the ring grooves constituting the multi ring-groove patterned face are set in the range of 0.5 to 2 mm and 10 to 100 mm, respectively.
1. A vitreous silica crucible for pulling a single-crystal silicon ingot, comprising a double layered structure constituted by an outer layer composed of high-purity amorphous vitreous silica with a bubble content of 1 to 10% and a purity of 99.99% or higher, and an inner layer composed of high-purity amorphous vitreous silica with a bubble content of 0.6% or less and a purity of 99.99% or higher,
wherein, with regard to an inner surface of the high-purity vitreous silica crucible, at least for the inner surface between ingot-pulling start line and ingot-pulling end line of a silicon melt surface,
(a) a longitudinal section of the inner wall surface is in the shape of the wave to be a multi ring-groove patterned face, and
(b) depth of the ring grooves constituting the multi ring-groove patterned face is set in the range of 0.5 to 2 mm and width of the ring grooves constituting the multi ring-groove patterned face is set in the range of 10 to 100 mm, respectively, such that pinhole defects in the large-diameter single-crystal silicon ingot are reduced.
2. The vitreous silica crucible of claim 1 , wherein the vitreous silica crucible has an outer diameter of 610 to 810 mm.