Titania-doped quartz glass and making method, EUV lithographic member and photomask substrate
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsShigeru Maida, Motoyuki Yamada
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Abstract
A titania-doped quartz glass containing 3-12 wt % of titania at a titania concentration gradient less than or equal to 0.01 wt %/μm and having an apparent transmittance to 440 nm wavelength light of at least 30% at a thickness of 6.35 mm is of such homogeneity that it provides a high surface accuracy as required for EUV lithographic members, typically EUV lithographic photomask substrates.
Claims13
A titania-doped quartz glass containing 3 to 12% by weight of titania at a titania concentration gradient less than or equal to 0.01 wt %/μm and having an apparent transmittance to 440 nm wavelength light of at least 30% at a thickness of 6.35 mm.
Dependencies are inferred from the claim text.