Nikon Corporation

Hiroki Jinbo

Norio Komine

Seishi Fujiwara

Hiroyuki Hiraiwa

Akiko Yoshida

Kazuhiro Nakagawa

Satoru Oshikawa

Norihisa Yamaguchi

Issey Tanaka

Shigeru Sakuma

Masafumi Mizuguchi

Shouji Yajima

Jun Takano

Akiko Moriya

Masaki Shiozawa

Tsutomu Mizugaki

Toshitsugu Suwa

A silica glass member of the present invention is one wherein when a composition thereof is expressed by SiO , 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&times;10 molecules/cm nor more than 5&times;10 molecules/cm , and wherein a difference A&minus;B between an absorption coefficient A immediately before an end of irradiation with 1&times;10 pulses of ArF excimer laser light in an average one-pulse energy density of 2 mJ/cm 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 . 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.

Quartz glass member and projection aligner

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&times;10 pulse irradiation with an ArF excimer laser at an energy density from 0.1 &mgr;J/cm &middot;p to 200 mJ/cm &middot;p, have a loss factor no greater than 0.0050 cm at 193.4 nm measured after irradiation, a hydrogen molecule concentration from 1&times;10 molecules/cm to 2&times;10 molecules/cm and a loss factor no greater than 0.0020 cm before ultraviolet irradiation.

Synthetic silica glass member, photolithography apparatus and process for producing photolithography apparatus

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&times;10 molecules/cm or less concentration of formyl radical generated by X-ray irradiation whose dose is 0.01 Mrad or more and 1 Mrad or less.

Optical member made of silica glass, method for manufacturing silica glass, and reduction projection exposure apparatus using the optical member

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.

Optical system with improved durability for projection exposure apparatus and method for manufacturing optical system for projection exposure apparatus

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 &lsqb;%/cm&rsqb; 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.

UV synthetic silica glass optical member and reduction projection exposure apparatus using the same

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.

Exposure apparatus including silica glass and method for producing silica glass

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.

Forming method of silica glass and forming apparatus thereof

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&times;10 in terms of refractive index differential.

Silica glass member

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.

Synthetic silica glass and its manufacturing method

A method of manufacturing synthetic silica glass includes the steps of pressurizing a liquid storage tank including a liquid silicon compound therein, generating bubbles in the liquid silicon compound using a foamer, removing the bubbles using a degassed, displacing the liquid silicon compound into a vaporizer while controlling an amount of the liquid silicon compound displaced by a liquid mass flow meter, mixing the displaced liquid silicon compound with a carrier gas to generate a gaseous silicon compound, injecting the gaseous silicon compound into a synthesis furnace, and forming synthetic silica glass by hydrolyzing the gaseous silicon compound in the synthesis furnace.

Manufacturing method of synthetic silica glass

A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm to about 20 slm/cm . The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.

Silica glass and its manufacturing method

A silica glass is provided for use in an optical system processing an excimer laser beam. The silica glass has a molecular hydrogen concentration of about 5&times;10 molecules/cm or less and is substantially free from defects which become precursors susceptible to an one-photon absorption process and a two-photon absorption process upon irradiation of the excimer laser beam to the silica glass.

Silica glass having superior durability against excimer laser beams and method for manufacturing the same

A method is provided for evaluating a transmittance of an optical member for ultraviolet use, which is an object of measurement. The method includes the steps of cleaning the object of measurement, measuring a transmittance of the object of measurement within a predetermined time period from completion of the cleaning during which a rate of decrease in the transmittance of the object of measurement remains substantially constant, and correcting the transmittance measured in the step of measuring to a transmittance at an evaluation time arbitrarily selected within the predetermined time period in accordance with the constant rate of decrease in the transmittance and a time at which the transmittance is measured.

Method for measuring transmittance of optical members for ultraviolent use, synthetic silica glass, and photolithography apparatus using the same

A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm,to about 20 slm/cm,. The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.

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Yokohama, Japan

Hiroki Jinbo