Title:
LARGE-SIZED SYNTHETIC SILICA GLASS PLATE MATERIAL FOR HIGH-POWER VACUUM ULTRAVIOLET RADIATION AND ITS PRODUCTION
Document Type and Number:
Japanese Patent JP3630533
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain the subject glass plate material high in initial transmittance for high-power ultraviolet radiation by specifying the OH group concentration and OH group concentration variance per cm therein.
SOLUTION: A high-purity silicon compound such as CH3Si(OH2)3 is subjected to flame hydrolysis with e.g. oxyhydrogen gas and a large-sized soot is formed while uniformizing the axial OH group concentration by burner swing, which, in turn, is melted under heating in a vacuum atmosphere at 1,500-1,700°C to regulate the OH group concentration to make a cylindrical synthetic silica glass form 80-200 mm in outer diameter and 20-70 mm or so in wall thickness. Next, the cylindrical synthetic silica glass form is subjected to tube drawing while controlling the inner pressure thereof using N2 gas into a large-sized tube 200-400 mm in outer diameter and 3-10 mm or so in wall thickness, which is then notched axially at specified intervals, and then stretched tangentially while softening the tube under heating in the tube peripheral direction into a flat plate, thus obtaining the objective silica glass plate material 5-300 ppm in OH group concentration and ≤ 10 ppm in OH group concentration variance per cm.
Inventors:
Nobuo Ohashi
Kuriyama Mitsuha
Shigeru Yamagata
Shigemasa Sunada
Kuriyama Mitsuha
Shigeru Yamagata
Shigemasa Sunada
Application Number:
JP22445097A
Publication Date:
March 16, 2005
Filing Date:
August 07, 1997
Export Citation:
Assignee:
Shin-Etsu Quartz Products Co., Ltd.
International Classes:
C03B8/04; C03B19/09; C03B19/14; C03B20/00; C03C3/06; H01L21/304; (IPC1-7): C03B20/00; H01L21/304
Domestic Patent References:
| JP912323A | ||||
| JP280343A | ||||
| JP2102139A | ||||
| JP35339A | ||||
| JP1197343A | ||||
| JP8309343A | ||||
| JP3403317B2 |
Attorney, Agent or Firm:
Heihachi Hattori