| 摘要 |
Synthetic quartz glass is prepared by subjecting a silicon-providing feedstock to flame hydrolysis in oxyhydrogen flame, depositing silica fine particles on a rotating quartz glass target while concurrently melting and vitrifying them, thereby forming a synthetic quartz glass ingot, shaping, annealing, and effecting dehydrogenation treatment at a temperature of at least 600°C and a pressure of up to 5 Pa for a holding time of at least 12 hours. The synthetic quartz glass has an OH group concentration of at least 300 ppm and a Raman peak attributable to hydrogen molecule equal to or less than the detection limit of 8.5 x 10 15 molecules/cm 3 and thus has a high helium gas permeability and consequently is suited for forming nanoimprint molds. |
