Patent ID: 9150447
Filing Date: 2015-10-06
Classification: C03B,C03C,C30B,Y02P,Y10T

Abstract:
1. A silica crucible for pulling a silicon single crystal, comprising silica glass and having a two-layer structure of an outer layer and an inner layer, wherein when a height position of the bottom of the crucible is 0 and a height position of the upper opening end of the crucible is 100 in a sectional side view of the crucible, the start position for the pulling of the silicon single crystal is within a height position range of 50 to 95 from the bottom of the crucible and the end position for the pulling of the silicon single crystal is within a height position range of 0 to 10 from the bottom of the crucible, wherein the inner layer, in a sectional side view of the crucible, has a wavy inner surface shape having mountain parts and valley parts at least between the start position and the end position for the pulling of a silicon single crystal in a silicon melt surface, the wavy inner surface shape is formed of an amorphous structure, and when a distance from an upper opening end of the crucible to the start position for the pulling of the silicon single crystal is 100, only a crucible portion from the upper opening end to a position within a range of 40 to 100 is crystalline, and wherein the crucible portion from the upper opening end to the position within the range of 40 to 100 does not have a crystallization promoter.