Fabrication of heavy walled silica tubing

Abstract

A method for producing a silica glass body having a low bubble content includes melting silica sand in a chamber (62) of a rotating furnace housing (20) to form molten silica. Helium-containing gas is fed into the chamber, both during introduction of the sand and during the heating step. The helium diffuses more readily from the molten silica than other gases, resulting in lower bubble content. The furnace is heated by establishing a gas plasma arc (60) between spaced electrodes (64, 66) within the chamber.

Description

technical field [0001] The present invention generally relates to quartz (SiO 2 ) glass, and more specifically, a thick-walled SiO with low bubble content 2 manufacturing. Background technique [0002] SiO, sometimes called "fused quartz" 2 Glass is used in a wide variety of applications. When it is in tubular form, it is used in semiconductor wafer processing. For example, the tube is shaped for use in high-purity containers used in the manufacture of semiconductor materials, ie for holding semiconductor materials during processing steps such as melting, zone refining, diffusion or epitaxy. For this and other applications, bubble-free and as homogeneous as possible transparent SiO 2 Glass is preferred. Transparent SiO 2 Other applications of glass include optical components such as light bulbs for high temperature, high brightness, and thus high efficiency, and energy propagation fibers for optical communication systems. [0003] For the manufacture of such tubing, ...

AI Technical Summary

Problems solved by technology

This method gives good results, but it increases processing time, especially when high optical quality is required, i.e. small bubble sizes

Images