Abstract: An exposure apparatus includes an illumination optical system configured to illuminate a mask by using a laser beam having a wavelength shorter than 250 nm as a light source, and a projection optical system configured to project and expose a pattern image of the mask onto an exposed substrate, in which an optical element made of a synthetic quartz member is disposed in the illumination optical system and/or the projection optical system. The synthetic quartz member satisfies the following conditions of initial transmittance relative to light having a wavelength of 150 nm being equal to or above 60% per centimeter, striae therein satisfying either grade 1 or grade 2 as defined in Japan Optical Glass Industry Society Standard (JOGIS), an absorption coefficient ? for an infrared absorption band of a hydroxyl group located at 3585 cm?1 being equal to or below 0.035/cm, and the content of aluminum being equal to or below 1 ppm while the content of lithium being equal to or below 0.5 ppm.

Abstract: An optical member made of silica glass manufactured by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame, said optical member having a 2×1014 molecules/cm3 or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.

Abstract: A silica glass member of the present invention is one wherein when a composition thereof is expressed by SiOx, x is not less than 1.85 nor more than 1.95, wherein a concentration of hydrogen molecules included therein is not less than 1×1016 molecules/cm3 nor more than 5×1018 molecules/cm3, and wherein a difference A−B between an absorption coefficient A immediately before an end of irradiation with 1×104 pulses of ArF excimer laser light in an average one-pulse energy density of 2 mJ/cm2 and a second absorption coefficient B at 600 seconds after a stop of the irradiation with the ArF excimer laser light is not more than 0.002 cm−1. When this silica glass member is applied to an illumination optical system and/or a projection optical system in projection exposure apparatus, it becomes feasible to implement uniform exposure while reducing variation in illuminance on a reticle surface and in an exposure area on a wafer.

Abstract: An optical member made of silica glass manufactured by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame,

Abstract: An optical member is provided for used by a photolithography projection system that has a sub-200 nm wavelength vacuum ultraviolet light source. The optical member includes silica glass that has an ArF excimer laser-induced bulk attenuation coefficient &Dgr;&ggr; that substantially satisfies the equation, &Dgr;&ggr;=ks·&egr;2·P1 when an ArF excimer laser with an energy density less than or equal to about 200 mJ/cm2 per pulse is used for illumination, where ks is less than about 9.1×10−13 cm−1, &egr; is per pulse energy density, P is pulse count, and ks is a proportionality constant.

Abstract: A photolithography apparatus has an exposure light source for emitting exposure light with a wavelength of 400 nm or less, a reticle with a pattern original image formed therein, an illumination optical system for illuminating the reticle with exposure light, a projection optical system for projecting the pattern image from the reticle onto a photosensitive plate and an alignment system for aligning the reticle and the photosensitive plate. At least some of the synthetic silica glass members composing the illumination optical system, the projection optical system and the reticle consist of synthetic silica glass members which, upon 1×104 pulse irradiation with an ArF excimer laser at an energy density from 0.1 &mgr;J/cm2·p to 200 mJ/cm2·p, have a loss factor no greater than 0.0050 cm−1 at 193.4 nm measured after irradiation, a hydrogen molecule concentration from 1×1016 molecules/cm3 to 2×1018 molecules/cm3 and a loss factor no greater than 0.

Abstract: An optical member made of silica glass manufactured by the direct method where a material gas comprising an organosilicon compound is allowed to react in an oxidizing flame, said optical member having a 2×1014 molecules/cm3 or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.

Abstract: A silica glass member of the present invention is one wherein when a composition thereof is expressed by SiOx, x is not less than 1.85 nor more than 1.95, wherein a concentration of hydrogen molecules included therein is not less than 1×1016 molecules/cm3 nor more than 5×1018 molecules/cm3, and wherein a difference A−B between an absorption coefficient A immediately before an end of irradiation with 1×104 pulses of ArF excimer laser light in an average one-pulse energy density of 2 mJ/cm2 and a second absorption coefficient B at 600 seconds after a stop of the irradiation with the ArF excimer laser light is not more than 0.002 cm−1. When this silica glass member is applied to an illumination optical system and/or a projection optical system in projection exposure apparatus, it becomes feasible to implement uniform exposure while reducing variation in illuminance on a reticle surface and in an exposure area on a wafer.

Abstract: An optical system is provided in a projection exposure apparatus for processing an excimer laser beam. The optical system includes at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less, and at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm.

Abstract: This invention provides a synthetic silica glass optical member used together with light having a specific wavelength of 250 nm or less, in which the difference between the maximum value and the minimum value of transmittance [%/cm] per cm in thickness for the light in a predetermined direction within a plane perpendicular to the optical axis is 2.0%/cm or less.

Abstract: A silica glass has a structure determination temperature of 1200 K or lower and an OH group concentration of at least 1,000 ppm. The silica glass is used for photolithography together with light in a wavelength region of 400 nm or shorter.

Abstract: The invention relates to fluorine-containing silica glasses, and methods of their production. The silica glass may be used for an ultraviolet light optical system in which light in a wavelength region of 200 mn or less, such as an ArF (193 nm) excimer laser, is used The invention also relates to a projection exposure apparatus containing fluorine-containing glass of the invention.

Abstract: A silica glass has a structure determination temperature of 1200 K or lower and an OH group concentration of at least 1,000 ppm. The silica glass is used for photolithography together with light in a wavelength region of 400 nm or shorter.

Abstract: A silica glass forming method is a method of pressing a synthetic silica bulk having at least a set of opposed surfaces, on the surfaces under a high temperature condition by a presser, wherein an elastic member with permeability is placed between the presser and the surfaces of the synthetic silica bulk pressed by the presser and wherein the synthetic silica bulk is pressed through the elastic member by the presser. This method is able to reduce bubbles remaining inside the synthetic glass formed product after the forming to a sufficiently small amount. Therefore, it becomes feasible to provide the method that permits high-yield production of silica glasses with excellent optical characteristics.

Abstract: A silica glass member is provided for use in an optical system using light of a wavelength equal to or less than about 400 nm as a light source. The silica glass member has striae in a direction different from an optical axis of the optical system. The strength of the striae is equal to or less than about 2×10−6 in terms of refractive index differential.

Abstract: A method is provided for manufacturing a synthetic silica glass. The method includes the steps of emitting an oxygen containing gas and a hydrogen containing gas from a burner; emitting a mixture of an organic silicon compound and a halogen compound from the burner; and reacting the mixture with the oxygen containing gas and the hydrogen containing gas to synthesize the silica glass.

Abstract: An optical system is provided in a projection exposure apparatus for processing an excimer laser beam. The optical system includes at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less, and at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm.

Abstract: A method is provided for manufacturing a synthetic silica glass. The method includes the steps of maintaining a silica glass member, which is formed using a flame hydrolysis method and having an OH group concentration of about 500 ppm to about 1300 ppm, at a predetermined holding temperature for a predetermined period of time so as to substantially relax the structure of the silica glass member. The method further includes the step of subsequently cooling the silica glass member to a first predetermined temperature at a cooling rate of about 10 K/hour or less, and thereafter, cooling the silica glass member to a second predetermined temperature at a cooling rate of about 1 K/hour or less. The method further includes the step of further cooling the silica glass member to a third predetermined temperature at a cooling rate of about 10 K/hour or less.

Abstract: A sync clock signal for information reproduction is generated using a binary signal obtained from a recording medium as a reference signal. The phase of the binary signal is compared with that of the sync clock signal. A frequency is changed based on the comparison result to generate (2m+1) multi-phase clock signals mutually shifted in phase by an integral multiple of 2&pgr;/(2m+1). Any one of these clock signals is used as the sync clock signal for information reproduction. The binary signal is delayed by a controllable delay time to generate a binary delayed signal, the phase of which is compared with those of the clock signals. The delay time of the binary delayed signal is controlled based on the comparison result so that the level change timing of the binary delayed signal is moved on a time base away from that of the sync clock signal.

Abstract: A photolithography apparatus is constructed comprising an exposure light source that emits light with a wavelength of 400 nm or less as the exposure light, a reticle with a pattern original image formed therein, an illumination optical system that irradiates light outputted from the exposure light source onto the reticle, a projection optical system that projects the pattern image outputted from the reticle onto a photosensitive plate and an alignment system that positions the reticle and the photosensitive plate. At least some of the synthetic silica glass members composing the illumination optical system, the synthetic silica glass members composing the projection optical system and the reticle consist of synthetic silica glass members which, upon 1×104 pulse irradiation with an ArF excimer laser at an energy density from 0.1 &mgr;J/cm2·p to 200 mJ/cm2·p, have a loss factor of no greater than 0.0050 cm−1 at 193.