Abstract: The claimed invention relates to a process for producing an optical material for EUV lithography, wherein the optical material contains a silica glass having a TiO2 concentration of from 3 to 12 mass % and a hydrogen molecule content of less than 5×1017 molecules/cm3 in the glass. The process including coating a multilayer film on the silica glass by ion beam sputtering.

Abstract: For a substrate having fine convexoconcave patterns on its surface, the dimensions of the convexoconcave patterns in a vertical direction of a quartz glass substrate are controlled to be uniform with extreme accuracy and over the entire substrate surface. The quartz glass substrate is made to have a fictive temperature distribution of at most 40° C. and a halogen concentration of less than 400 ppm, and the etching rate of the surface of the quartz glass substrate is made uniform, whereby the dimensions of the convexoconcave patterns in a vertical direction of the quartz glass substrate are controlled to be uniform with good accuracy and over the entire substrate surface.

Abstract: It is to obtain a silica glass suitable as a material for an optical material constituting an optical system to be used for EUVL, which has a low coefficient of thermal expansion from 0 to 100° C., and on which formation of concave defects is suppressed in a polishing step to achieve a high level of flatness. A silica glass containing from 0.1 to 10 mass % of Sn calculated as SnO2 and from 3 to 10 mass % of Ti calculated as TiO2, which has a homogeneity of the coefficient of thermal expansion from 0 to 100° C. to the temperature of from 50 to 200 ppb/° C., a coefficient of thermal expansion from 0 to 100° C. of 0±250 ppb/° C., and a Vickers hardness of at most 650.

Abstract: An object of the present invention is to provide an artificial quartz member inhibited from suffering the decrease in transmittance in a laser light wavelength region which is caused by long-term irradiation with a laser light having a wavelength of 200 nm or shorter; and a process for producing the artificial quartz member. The invention provides an artificial quartz member for use as an optical element to be irradiated with a laser light having a wavelength of 200 nm or shorter, having an aluminum content of 200 ppb or lower.

Abstract: It is to provide a photomask substrate which has a low birefringence and with which polarized illumination can be employed or immersion exposure can be carried out. A photomask substrate made of a synthetic quartz glass to be used for production of a semiconductor employing a light source having an exposure wavelength of at most about 200 nm, which has a birefringence of at most 1 nm/6.35 mm at the exposure wavelength, and of which the amount of decrease in light transmittance is at most 1.0% as a difference in light transmittance at a wavelength of 217 nm, between before and after irradiation with Xe excimer lamp with an illuminance of 13.2 mW/cm2 for 20 minutes.

Abstract: It is to provide a silica glass containing TiO2, having a wide temperature range wherein the coefficient of thermal expansion is substantially zero. A silica glass containing TiO2, which has a TiO2 concentration of from 3 to 10 mass %, a OH group concentration of at most 600 mass ppm and a Ti3+ concentration of at most 70 mass ppm, characterized by having a fictive temperature of at most 1,200° C., a coefficient of thermal expansion from 0 to 100° C. of 0±150 ppb/° C., and an internal transmittance T400-700 per 1 mm thickness in a wavelength range of from 400 to 700 nm of at least 80%. A process for producing a silica glass containing TiO2, which comprises porous glass body formation step, F-doping step, oxygen treatment step, densification step and vitrification step.

Abstract: It is to obtain a silica glass suitable as a material for an optical material constituting an optical system to be used for EUVL, which has a low coefficient of thermal expansion from 0 to 100° C., and on which formation of concave defects is suppressed in a polishing step to achieve a high level of flatness. A silica glass containing from 0.1 to 10 mass % of Sn calculated as SnO2 and from 3 to 10 mass % of Ti calculated as TiO2, which has a homogeneity of the coefficient of thermal expansion from 0 to 100° C. to the temperature of from 50 to 200 ppb/° C., a coefficient of thermal expansion from 0 to 100° C. of 0±250 ppb/° C., and a Vickers hardness of at most 650.

Abstract: For a substrate having fine convexoconcave patterns on its surface, the dimensions of the convexoconcave patterns in a vertical direction of a quartz glass substrate are controlled to be uniform with extreme accuracy and over the entire substrate surface. The quartz glass substrate is made to have a fictive temperature distribution of at most 40° C. and a halogen concentration of less than 400 ppm, and the etching rate of the surface of the quartz glass substrate is made uniform, whereby the dimensions of the convexoconcave patterns in a vertical direction of the quartz glass substrate are controlled to be uniform with good accuracy and over the entire substrate surface.

Abstract: To provide quartz-type glass for a microlithographic projection exposure apparatus, which contains at least 51 mass % of SiO2 and which further contains at least one member selected from the group consisting of lanthanum, aluminum, hafnium, nitrogen, scandium, yttrium and zirconium. It is a material which is useful for an illumination system for a microlithographic projection exposure apparatus or as a projection object lens and has a refractive index at 248 nm larger than 1.508 of quartz glass and a refractive index at 193 nm larger than 1.560 of quartz glass and which can be small-sized.

Abstract: The present invention provides a mask blank which comprises a substrate made of a synthetic quartz glass and a light-shielding film laminated on a surface of the substrate and is for use in a semiconductor device production technique employing an exposure light wavelength of 200 nm or shorter, wherein the mask blank has a birefringence, as measured at a wavelength of 193 nm, of 1 nm or less per substrate thickness. According to the present invention, mask blanks suitable for use in the immersion exposure technique and the polarized illumination technique are provided.

Abstract: Conventional TiO2—SiO2 glass contains hydrogen atoms substantially, and during deposition under ultrahigh vacuum condition, the hydrogen molecules will diffuse in the chamber, and H2 molecules will be taken into a film thereby formed. Hydrogen molecules will readily diffuse, and the optical characteristics of the multilayer film are likely to be thereby changed. In an optical material for EUV lithography, a multilayer film is coated by ion beam sputtering on a silica glass having a TiO2 concentration of from 3 to 12 mass % and a hydrogen molecule content of less than 5×1017 molecules/cm3 in the glass.

Abstract: It is to provide a silica glass containing TiO2, having a wide temperature range wherein the coefficient of thermal expansion is substantially zero. A silica glass containing TiO2, which has a TiO2 concentration of from 3 to 10 mass %, a OH group concentration of at most 600 mass ppm and a Ti3+ concentration of at most 70 mass ppm, characterized by having a fictive temperature of at most 1,200° C., a coefficient of thermal expansion from 0 to 100° C. of 0±150 ppb/° C., and an internal transmittance T400-700 per 1 mm thickness in a wavelength range of from 400 to 700 nm of at least 80%. A process for producing a silica glass containing TiO2, which comprises porous glass body formation step, F-doping step, oxygen treatment step, densification step and vitrification step.

Abstract: To reduce the change in the refractive index of an irradiated portion of synthetic quartz glass, caused by the irradiation with a high energy light emitted from a light source such as a KrF excimer laser or an ArF excimer laser. A process for producing an optical member made of synthetic quartz glass, wherein the OH group concentration of the optical member is set depending upon the energy density of the laser beam employed, to adjust the ratio R (KJ/cm2-ppb)?1 of the change in the refractive index of the optical member to the cumulative irradiation energy (KJ/cm2) by the laser, to be 0?R?0.2, thereby to control the change in the refractive index of the optical member made of synthetic quartz glass by the irradiation with a laser beam to be within a predetermined range.

Abstract: It is to provide a photomask substrate which has a low birefringence and with which polarized illumination can be employed or immersion exposure can be carried out. A photomask substrate made of a synthetic quartz glass to be used for production of a semiconductor employing a light source having an exposure wavelength of at most about 200 nm, which has a birefringence of at most 1 nm/6.35 mm at the exposure wavelength, and of which the amount of decrease in light transmittance is at most 1.0% as a difference in light transmittance at a wavelength of 217 nm, between before and after irradiation with Xe excimer lamp with an illuminance of 13.2 mW/cm2 for 20 minutes.

Abstract: A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm?1 (I2250) to the scattering peak intensity of 800 cm?1 (I800), i.e. I2250/I800, of at most 1×10?4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10?3 cm?1.

Abstract: An antireflection substrate comprising a substrate which is transparent to ultraviolet and vacuum ultraviolet rays in the wavelength region from 155 nm to 200 nm and a mono-, bi- or tri-layer antireflection film formed on at least one side of the substrate, wherein the refractive index and the physical thickness of the antireflection film at the center wavelength &lgr;0 of the wavelength region of ultraviolet or vacuum ultraviolet light which needs antireflection satisfy particular conditions, and an optical component for a semiconductor manufacturing apparatus and a substrate for a low-reflection pellicle which is the ultraviolet and vacuum ultraviolet antireflection substrate.

Abstract: A structure for attaching a pellicle to a photomask, the pellicle comprising a pellicle frame and a pellicle sheet attached to an opening portion formed in the pellicle frame, wherein at least a portion of the pellicle frame surface in contact with the photo-mask has a direct contact with the photo-mask without interposing an adhesive.

Abstract: A pellicle comprising a box-shaped pellicle frame having top and bottom openings, and a pellicle sheet bonded to the pellicle frame to cover one of the openings of the pellicle frame, wherein the pellicle frame is made of quartz glass, a plurality of vent holes are formed as distributed on opposing side walls of the pellicle frame, and the size of the vent holes in the direction of the height of the pellicle frame is at most ⅗ of the height of the pellicle frame.

Abstract: A pellicle formed by bonding a pellicle membrane composed of synthesized glass on a pellicle frame by an adhesive wherein a light shielding member for shielding ultra-violet rays irradiated to the adhesive is provided at a portion where the pellicle membrane is bonded to the pellicle frame, whereby the adhesive for bonding the pellicle membrane to the pellicle frame is prevented from being deteriorated due to the irradiation of ultra-violet rays for cleaning.

Abstract: An antireflection substrate comprising a substrate which is transparent to ultraviolet and vacuum ultraviolet rays in the wavelength region from 155 nm to 200 nm and a mono-, bi- or tri-layer antireflection film formed on at least one side of the substrate, wherein the refractive index and the physical thickness of the antireflection film at the center wavelength &lgr;0 of the wavelength region of ultraviolet or vacuum ultraviolet light which needs antireflection satisfy particular conditions, and an optical component for a semiconductor manufacturing apparatus and a substrate for a low-reflection pellicle which is the ultraviolet and vacuum ultraviolet antireflection substrate