Patent ID: 6797061
Filing Date: 2004-09-28
Classification: C03B,C30B,Y10S,Y10T

Abstract:
A quartz glass crucible for pulling up a silicon single crystal, comprising a crucible base body constituted of a semi-transparent quartz glass layer and a transparent quartz glass layer formed on an inner wall surface of the crucible base body, characterized in that no expanded bubbles equal to or more than 0.5 mm in diameter are present in a layer 1 mm in depth from an inner surface of the quartz glass crucible after the silicon single crystal is pulled up using the quartz glass crucible, wherein, with an arc rotation melting method, the base body is prepared in a mold using silicon dioxide powder and an inner layer is formed on an inner surface of the base body using silicon dioxide powder under conditions that the silicon dioxide powder has a gas content equal to or less than 30 &mgr;l/g and an OH group concentration equal to or less than 300 ppm, a heat melting power is applied in the range of 400 to 1000 kw, a horizontal distance from an arc center to a falling position of the silicon dioxide powder is in the range of 50 to 300 mm, a distance from the arc center to an inner surface of piled-up powder on a bottom of the base body is equal to or less than 800 mm, a particle diameter of the silicon dioxide powder is equal to or less than 300 &mgr;m, and a feed rate of the silicon dioxide powder is equal to or less than 200 g/min.