Abstract: A method for measuring trace quantities of OH groups in quartz glass comprises preparing a set of test pieces comprising a reference test piece from a blank of a quartz glass body whose OH group content is known and a sample test piece from a quartz glass body whose OH group content is to be measured, having two planar planes faced to each other, setting the sample test piece and the reference test piece in an infrared spectrophotometer; successively irradiating perpendicular to one of the two planar planes an incident infrared radiation in a wavelength region of approximately 2500 nm to approximately 2950 nm, while simultaneously detecting the outgoing radiation spectrum from the other plane; obtaining the difference of the outgoing radiation spectrum of each of the test pieces; selecting the absorbance peak assigned to OH groups at a wavelength of 2720 nm to obtain the peak height thereof; and calculating the concentration of OH groups from the peak height in the sample test piece.

Abstract: The present invention relates to an outer-diameter blade, an inner-diameter blade and cutting machines which respectively use the outer-diameter blade and the inner-diameter blade for cutting hard material, such as metal, ceramics, semiconductor single crystal, glass, quartz crystal, stone, asphalt or concrete, and a core drill and a core-drill processing machine which drives the core drill for forming a hole in the hard material.

Abstract: A core drill having a shank and a cup shaped base metal section constructed of a disk shaped top wall and a cylindrical side wall provided on a fore-end of the shank. A grinding stone portion is mounted on an outer end part of the base metal section, with abrasive grains fixed to the outer end part of the base metal section. Abrasive grain layers are formed in a spiral pattern on inner and outer side surfaces of the cylindrical side wall of the base metal section, with abrasive grains fixed to the inner and outer side surfaces of the cylindrical side wall thereof. When the grinding stone portion is put into rotational contact with a workpiece, the workpiece is ground through to form a circle hole in section leaving a cylindrical core therein.

Abstract: A method for heat treating a synthetic quartz glass for optical use in a heating furnace, that comprises covering the surroundings of a synthetic quartz glass body with a SiO2 powder having a mean dissolved hydrogen molecule concentration of 1×1019 molecules/cm3 or higher, and then heat treating the body.

Abstract: A synthetic quartz glass member having (i) a change of transmittance at 193 nm of up to 0.002 cm−1 as expressed in extinction coefficient when 4×104 shots of ArF excimer laser light are irradiated at 2 mJ/cm2/pulse, (ii) an initial transmittance of at least 99.6% at 193 nm, (iii) a hydrogen molecule content of at least 5×1017 molecules/cm3, (iv) a refractive index amplitude of up to 1×10−6, and (v) a birefringence of up to 1 nm/cm finds use in an excimer laser because it experiences a minimized change of light transmittance.

Abstract: A quartz glass member for use in dry etching, wherein at least the inner surface of the member to be brought into contact with plasma is constructed of synthetic quartz glass, and a dry etching system equipped with the same member. A dry etching system equipped with the quartz glass member, which minimizes the generation of particles and which prevent a drop in electrical characteristics from occurring on the silicon wafer.

Abstract: A method for producing an optical quartz glass for use in excimer lasers, comprising a step of forming a porous silica preform by depositing silica in a soot-like form formed by flame hydrolysis of a high-purity volatile silicon compound, followed by a step of vitrifying said porous silica preform into transparent glass in an atmosphere containing water vapor and hydrogen, and a vertical type heating furnace for carrying out the production method therein.

Abstract: The present invention relates to a synthetic quartz glass, which is a material for producing an optical member having an excellent excimer laser resistance, and a production method thereof with a good productivity. That is, the synthetic quartz glass produced by vitrifying glass fine particles obtained by flame hydrolysis of an organodisilazane compound directly on a substrate having a birefringence index of 5 nm/cm or less, a refractive index difference (&Dgr;n) of 2×10−6/cm or less, and an ArF saturated absorbance of 0.05/cm or less at a pulse energy density of 100 mJ/cm2/pulse.

Abstract: A method for welding a dummy tube to a quartz glass tube for use as an optical fiber preform, comprising chamfering the inner edge portion of the dummy tube and/or the quartz glass tube for use as the optical fiber preform before welding the quartz glass tube for use as the optical fiber preform with the dummy tube, and then melt welding them together.

Abstract: An optical system for integrated circuit fabrication comprises optical members made of synthetic quartz glass and fluorite, wherein: an optical member disposed in a position through which laser light is transmitted at a high light energy density, is made of single crystal fluorite; and an optical member in a position through which laser light is transmitted at a low light energy density, is made of synthetic quartz glass containing approximately such a hydrogen molecule concentration as can be doped under atmospheric pressure.

Abstract: 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 (&Dgr;n) in a plane orthogonal to the optical axis is up to about 1×10−6, the distribution of refractive index (&Dgr;n) 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.

Abstract: A silica glass optical material for projection lens to be used in vacuum ultraviolet radiation lithography using radiation from 155 to 195 nm in wavelength, wherein, said silica glass optical material is of ultrahigh purity, contains from 1 to 10 wtppm of OH groups, from 100 to 10,000 wtppm of F, and from 1×1017 to 1×1019 molecules/cm3 of H2, and has a distribution in concentration of F that is axially symmetrical to the central axis.

Abstract: A quartz glass jig having large irregularities on the surface thereof, wherein said irregularities have a center line roughness Ra in the range of from 2 to 30 &mgr;m, a maximum height Rmax in the range of from 10 to 150 &mgr;m, and a width in the range of from 10 to 500 &mgr;m, and by a method which comprises forming an inorganic thin film on the surface of a quartz glass jig free from microcracks and having fine irregularities on the surface thereof and thereafter rinsing it a plurality of times.

Abstract: A silica glass optical material for transmitting light with a wavelength of from 155 to 195 nm emitted from an excimer laser or an excimer lamp, which comprises silica glass optical material of ultrahigh purity, containing from 1 to 100 wtppm of OH groups, from 5×1016 to 5×1019 molecules/cm3 of H2, and from 10 to 10,000 wtppm of F, but substantially free from halogens other than F, and having a fluctuation in refractive index, &Dgr;n, of from 3×10−6 to 3×10−7.

Abstract: A method for producing an optical fiber preform comprising inserting a core glass rod for use in the optical fiber preform into the quartz glass tube for the optical fiber preform and then welding them in a heating furnace to melt weld them together into a monolithic product, wherein the melting is started in such a state that the lower open edge of said quartz glass tube is placed inside the heating furnace and a gas is supplied from the upper edge of the tube, and after the lower edge portion of the quartz glass tube is drawn out from said heating furnace by melt deformation and stretching by the gravitational force, the gas supply is cut off and the pressure is reduced.

Abstract: Provided are a quartz glass crucible for pulling up a silicon single crystal, with which not only a defectless silicon single crystal can be pulled up but a single crystallization ratio can greatly be improved, and a production method therefor.

Abstract: An efficient method is proposed for the utilization of heretofore useless extremely fine fluffy silica particles obtained as a flue dust in the flame-hydrolysis of vaporizable silicon compound in an oxyhydrogen flame in the manufacturing process of fused silica glass. The method comprises the steps of (a) uniformly mixing the silica particles with water, (b) drying the wet mixture under specified conditions to give dried cakes of the silica particles, (c) disintegrating the dried cakes into porous silica beads having an appropriate particle diameter, (d) semi-sintering the porous silica beads at 800 to 1300° C. and (e) vitrifying the semi-sintered silica beads at 1350 to 1550° C. into vitrified poreless silica glass particles which can be used as a base material for the production of fused silica glass articles.

Abstract: There is provided a quartz glass crucible for pulling a silicon single crystal and a production process for the crucible, wherein an inner surface of the crucible is crystallized without addition of impurities during pulling a silicon single crystal, thereby impurities serving as causes of crystal defects being not incorporated into the silicon single crystal, so that deterioration of its inner surface is suppressed to improve a crystallization ratio, and accordingly productivity of the quartz glass crucible as well as a quality of the silicon single crystal is improved, and the quartz glass crucible for pulling a silicon single crystal comprises a crucible base body (3) made of a translucent quartz glass layer and a synthetic quartz glass layer (4) formed on an inner wall surface of the crucible base body (3), wherein a portion encircled by a brown ring on an inner surface of the quartz glass crucible is uniformly crystallized during pulling the silicon single crystal.

Abstract: A simple method for producing a synthetic quartz glass having excellent homogeneity and high transmittance, which is useful as an optical material in producing steppers equipped with an ArF excimer laser as a radiation source. A method for producing a synthetic quartz glass for use in ArF excimer laser lithography, which comprises irradiating a highly homogeneous synthetic quartz glass containing less than 60 ppb of Na with ultraviolet radiation having a maximum wavelength of 260 nm for not less than the duration expressed by the equation: Y=(80X−1880)/Z wherein X represents an Na concentration (ppb), Y represents the duration of irradiation (hours), and Z represents the illuminance of an ultraviolet radiation on an irradiated surface (mW/cm2).

Abstract: A method of producing an optical component for the transmission of UV light is provided. An optical fiber is prepared from synthetic quartz glass or from doped synthetic quartz glass with a transmission region for the transmission of UV light, and the transmission region is charged with hydrogen and/or with deuterium. The charging includes coating the fiber with a blocking layer inhibiting hydrogen diffusion, and charging the fiber in an atmosphere containing hydrogen and/or deuterium. This atmosphere is under a pressure in the range from 0.1 MPa to 200 MPa and at a temperature between 100° C. and 800° C. so as to produce a concentration of said hydrogen and/or deuterium of at least 5×1019 molecules/cm3 in the transmission region. The coating and charging steps may be performed repeatedly, and the blocking layer is built up to comprise a plurality of thinner layers including a top layer, after application of which charging is discontinued.