Deuteroxyle-doped silica glass, optical member and lithographic system comprising same and method of making same
OwnerDana Bookbinder, Richard Fiaccoinventors
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Abstract
What is disclosed includes OD-doped synthetic silica glass capable of being used in optical elements for use in lithography below about 300 nm. OD-doped synthetic silica glass was found to have significantly lower polarization-induced birefringence value than non-OD-doped silica glass with comparable concentration of OH. Also disclosed are processes for making OD-dopes synthetic silica glasses, optical member comprising such glasses, and lithographic systems comprising such optical member. The glass is particularly suitable for immersion lithographic systems due to the exceptionally low polarization-induced birefringence values at about 193 nm.
Claims111
An OD-doped synthetic silica glass material capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below about 300 nm comprising OD and optionally OH, wherein the ratio of n(OD)/(n(OD)+n(OH)) is higher than 2×10−4.
A process for making OD-doped synthetic silica glass material capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below about 300 nm, comprising the following steps:
- (I) providing a plurality of particles comprising silica;
- (II) depositing the plurality of particles on a supportive deposition surface at an elevated temperature such that the particles are consolidated into transparent glass material in situ,
- wherein:
- either in step (I), the plurality of particles provided are D-containing and/or in step (II), the deposition and consolidation are carried out in an D-containing atmosphere,
- such that the obtained silica glass comprises OD and optionally OH, and the ratio of n(OD)/(n(OD)+n(OH)) is higher than about 2×10−4.
A process for making OD-doped synthetic silica glass material capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below about 300 nm, comprising the following steps:
- (A) providing a particle preform comprising a plurality of particles comprising silica;
- (B) optionally purifying and/or drying the particle preform;
- (C) optionally further doping the particle preform with dopants;
- (D) consolidating the particle preform at an elevated temperature to dense glass;
- and
- (E) optionally treating the consolidated glass obtained in step (D) in the presence of H2, HD and/or D2,
- wherein in at least one of steps (A), (B), (C), (D) and (E), OD is introduced or formed into the glass.
A process according to clam 97, wherein step (E) is carried out in an atmosphere essentially devoid of H2.
A process for making OD-doped synthetic silica glass capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below about 300 nm, comprising the following steps:
- (a) providing a plurality of OD-doped particles comprising silica;
- and
- (b) melting the particles at an elevated temperature to obtain a transparent glass.
A process for making OD-doped synthetic silica glass capable of being used in the light path of the lithographic irradiation of a lithographic device operating at a wavelength below about 300 nm, comprising the following steps:
- (a) providing at least one consolidated OD-doped silica glass;
- (b) melting the OD-doped silica glass and homogenizing it at an elevated temperature to obtain a glass having an essentially uniformly distributed [OD] and/or [OH] therein.
Dependencies are inferred from the claim text.