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AssigneesHeraeus Quarzglas GmbH & Co. KG, Shin-Etsu Quartz Products Co., Ltd.
InventorsNorio Ohashi, Michiyo Kuriyama, Shigeru Yamagata, Shigemasa Sunada
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An object of the present invention is to provide a synthetic silica glass optical material which exhibits excellent transmittance as well as durability for high output power vacuum ultraviolet rays, being emitted from, for example, ArF excimer lasers and Xe.sub.2 excimer lamps, and to provide a method for producing the same. A synthetic silica glass optical material for high output power vacuum ultraviolet rays made from ultra high purity synthetic silica glass for use in the wavelength region of from 165 to 195 nm, containing OH groups at a concentration of from 5 to 300 wtppm with a fluctuation width in OH group concentration (.DELTA.OH/cm) of 10 wtppm or less, containing hydrogen molecules at a concentration of from 1.times.10.sup.17 to 1.times.10.sup.19 molecule/cm.sup.3 with a fluctuation width in hydrogen molecule concentration (.DELTA.H.sub.2 /cm) of 1.times.10.sup.17 molecule/cm.sup.3 or lower, and containing chlorine at a concentration of 50 wtppm or lower. Also claimed is a method for producing the same.
A synthetic silica glass optical material for use with ultraviolet rays in the wavelength region from 165 to 195 nm, made from ultra-high purity synthetic silica glass, containing OH groups at a concentration of from 5 to 300 wtppm with a fluctuation in OH-group concentration (.DELTA.OH/cm) equal to or less than 10 wtppm, containing hydrogen molecules at a concentration of from 1.times.10.sup.17 to 1.times.10.sup.19 molecule/cm.sup.3 with a fluctuation in hydrogen molecule concentration (.DELTA.H.sub.2 /cm) equal to or less than 1.times.10.sup.17 molecule/cm.sup.3, and containing chlorine at a concentration equal to or less than 50 wtppm.
A synthetic silica glass optical material for use with ultraviolet rays in the wavelength region from 165 to 175 nm, made from ultra-high purity synthetic silica glass, containing OH groups at a concentration of from 5 to 100 wtppm with a fluctuation in OH-group concentration (.DELTA.OH/cm) equal to or less than 10 wtppm, containing hydrogen molecules at a concentration of from 1.times.10.sup.17 to 1.times.10.sup.19 molecule/cm.sup.3 with a fluctuation in hydrogen molecule concentration (.DELTA.H.sub.2 /cm) equal to or less than 1.times.10.sup.17 molecule/cm.sup.3, and containing chlorine at a concentration equal to or less than 50 wtppm.
Dependencies are inferred from the claim text.