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AssigneesHeraeus Quarzglas GmbH & Co. KG, Shin-Etsu Quartz Products Co., Ltd.
InventorsAkira Fujinoki, Takayuki Oshima, Hiroyuki Nishimura, Yasuyuki Yaginuma
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A synthetic glass member for use in excimer laser lithography, having superior homogeneity, high transmittance for ArF excimer laser beams and an excellent resistance against lasers is made from high purity synthetic quartz glass, and it is characterized in that layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index (Δn) in a plane orthogonal to the optical axis is up to about 1×10−6, the distribution of refractive index (Δn) in a plane parallel to the optical axis is up to about 5×10−6, the birefringence is up to about 2 nm/cm, the hydrogen molecule concentration is at least about 2×1017 molecules/cm3, and the internal transmittance is at least about 99.8% at a wavelength of 193.4 nm.
A synthetic quartz glass member for use in ArF excimer laser lithography comprising a high purity synthetic quartz glass and wherein layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index (Δn) in a plane orthogonal to the optical axis is 1×10−6 or less, the distribution of refractive index (Δn) in a plane parallel to the optical axis is 5×10−6 or less, the birefringence is 2 nm/cm or lower, the hydrogen molecule concentration is 2×1017 molecules/cm3 or higher, and the internal transmittance for wavelength at 193.4 nm is 99.8% or higher, wherein the synthetic quartz glass member shows an outer surface surrounding a bulk glass material, whereby there exists a Na concentration distribution such that the Na concentration is as high as 25 to 60 wt.-ppb at the outer surface and decreasing toward the bulk glass material, and whereby the synthetic quartz glass member was irradiated by ultraviolet rays at a wavelength of 260 nm or less and at an irradiation dose of at least 10 mW/cm2 for at least 48 hours.
A synthetic quartz glass member for use in ArF excimer laser lithography comprising a high purity synthetic quartz glass and wherein layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index (Δn) in a plane orthogonal to the optical axis is 1×10−6 or less, the distribution of refractive index (Δn) in a plane parallel to the optical axis is 5×10−6 or less, the birefringence is 2 nm/cm or lower, the hydrogen molecule concentration is 2×1017 molecules/cm3 or higher, and the internal transmittance for wavelength at 193.4 nm is 99.8% or higher, wherein the surface roughness Rmax of the synthetic quartz glass member is 30 μm or less.
A synthetic quartz glass member for use in ArF excimer laser lithography, having a distribution of refractive index (Δn) in a plane orthogonal to the optical axis of 1×10−6 or less, a distribution of refractive index (Δn) in a plane parallel to the optical axis of 5×10−6 or less, and a birefringence is being 2 nm/cm or lower, and an internal transmittance at a wavelength of 193.4 nm of 99.8% or higher, said synthetic quartz glass member having an outer surface surrounding a bulk glass material, said synthetic quartz glass member having a hydrogen molecule concentration of 2×1017 molecules/cm3 or higher, and a Na concentration distribution with about 25 to 60 wt.-ppb at the outer surface and decreasing toward the bulk glass material, the synthetic quartz glass member being irradiated by ultraviolet rays at a wavelength of 260 nm or less and at an irradiation dose of at least 10 mW/cm2 for at least 48 hours.
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