| 摘要 |
PURPOSE:To make rays of radiant light from a heat source to be scattered properly, and to heat contents in the quartz glass core tube for manufacture of the semiconductor uniformly by a method wherein nearly globular air bubbles of 10-50mum diameter remaining in quartz glass are made to be contained by 5,000 pieces or more per 1cm<3> when quartz glass is to be molten. CONSTITUTION:High pure quartz powder containing 80% or more of 20-60 mesh powder is filled up in an iron cylinder rotating the cylinder and using a core. Material powder is pressed to the outside wall according to centrifugal force, a carbon electrode is inserted in the hollow part thereof to heat turning on electricity, and the quartz glass tube is obtained. Nearly globular air bubbles of 10-50mum diameter exist therein by about 15,000 pieces per 1cm<3>, and when the tube thereof is used as the core tube for a semiconductor diffusion furnace with no liner tube, control of the temperature in the range of + or -1 deg.C in the prescribed temperature region can be attained, and no difference was observed in regard to the purity from a transparent quartz glass product. |
