Abstract: High purity silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a “dry,” silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: A synthetic quartz powder obtained by calcining a powder of silica gel, characterized in that white devitrification spots having sizes of larger than 20 &mgr;m in diameter formed in an ingot obtained by vacuum melting the synthetic quartz powder at a temperature of from 1780 to 1800° C. to form an ingot, followed by maintaining the ingot at a temperature of 1630° C. for 5 hours, are at most 10 spots/50 g.

Abstract: 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 5×1018 molecules/cm3 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.

Abstract: A probe for a surface-enhanced Raman scattering spectrometer is provided for injection into a cell in order to detect trace amounts of a compound within that cell. The probe has a spherical shape with a diameter less than one micrometer and preferably in the 10-500 nanometer range. The nanoprobes can have a receptor coating related to the specific compound to be detected by the probe. A process for producing, injecting and utilizing the nanoprobes are described.

Abstract: In a method for evaluating the homogeneity of the refractive index of an optical member, the refractive index distribution of the optical member is measured, the measured refractive index distribution is separated into a rotationally symmetric element and a non-rotationally symmetric element in the optical axis direction before or after correction of the power element, and the rotationally symmetric element is further subjected to 2nd/4th-order element correction. Upon execution of such comprehensive evaluation, a photolithography optical member, which can realize a fine, sharp exposure-transfer pattern (e.g., a line width of 0.3 &mgr;m or less) is provided.

Abstract: 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 5×1018 molecules/cm3 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.

Abstract: This ultralow-loss glass is characterized in that high purity silica glass contains 1 to 500 wt.ppm of at least one network modifying oxide. It is assumed that the network modifying oxide appropriately loosens the tetrahedral network structure of silica and hence Rayleigh scattering is decreased. Examples of the network modifying oxide include Na.sub.2 O, K.sub.2 O, Li.sub.2 O, MgO, CaO, and PbO. Since Rayleigh scattering losses are minimal in comparison with those of high purity silica glass, this impurity-added silica glass is excellent as a base material of a glass fiber for a long-distance transmission.

Abstract: An object of the present invention is to provide a synthetic silica glass optical material which exhibits excellent transmittance as well as durability for high output power vacuum ultraviolet rays, being emitted from, for example, ArF excimer lasers and Xe.sub.2 excimer lamps, and to provide a method for producing the same. A synthetic silica glass optical material for high output power vacuum ultraviolet rays made from ultra high purity synthetic silica glass for use in the wavelength region of from 165 to 195 nm, containing OH groups at a concentration of from 5 to 300 wtppm with a fluctuation width in OH group concentration (.DELTA.OH/cm) of 10 wtppm or less, containing hydrogen molecules at a concentration of from 1.times.10.sup.17 to 1.times.10.sup.19 molecule/cm.sup.3 with a fluctuation width in hydrogen molecule concentration (.DELTA.H.sub.2 /cm) of 1.times.10.sup.17 molecule/cm.sup.3 or lower, and containing chlorine at a concentration of 50 wtppm or lower.

Abstract: A metal halide or mercury lamp including an arc tube comprised of a glass composition consisting essentially of at least 90 weight percent SiO.sub.2 and including between about 10 and 1000 parts per million of a trivalent element slected from the group consisting of Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Unq, Unp, Ga, and mixtures thereof such that the viscosity of the glass composition is greater than 10.sup.14.5 poise at 1100.degree. C.

Abstract: A high-purity transparent silica glass containing Fe, Na and K impurities each in an amount of 0.01-0.3 ppm, and an OH group in an amount of 0-3 ppm; among the Fe impurities, the content of metallic Fe having a valency of +0 being not larger than 0.1 ppm. This transparent silica glass exhibits, even when it is maintained at 900-1,400.degree. C. for at least 20 hours, an extinction coefficient of not larger than 0.009 at a wavelength of 400 nm, and does not become colored as visually examined. The silica glass is made by a process wherein powdery silica filled in a mold cavity is melted at 1,700.degree. C. or higher, characterized in that the melting is conducted in a graphite mold having a porous high-purity graphite layer provided on the mold inner surface so that the filled silica is not contacted with the mold; said porous layer having a bulk density of 0.1-1.5 g/cm.sup.3, and the content of each of Fe, Na and K impurities in the porous layer being not larger than 1 ppm.

Abstract: A method for producing a machinable feldspathic porcelain comprising leucite is presented. Machinability is imparted to feldspathic porcelains by achieving homogeneous distribution of fine crystalline constituent comprised of at least one of the following leucite phases: potassium tetragonal leucite, rubidium leucite, cesium stabilized cubic leucite, rubidium stabilized cubic leucite, and pollucite. The porcelains produced in accordance with the present invention are readily machinable by using available diamond tooling techniques. Furthermore, the porcelains are especially useful for the fabrication of dental restorations using CAD/CAM technology.

Abstract: A process for producing a synthetic quartz powder, which comprises a step of heat-treating a silica gel powder while permitting it to flow in a rotary kiln.

Abstract: A process for producing synthetic quartz powder which comprises calcining silica gel powder to produce a synthetic quartz glass powder, wherein dry air is used in the calcining process at least in the process of cooling from 800.degree. C. to 200.degree. C. This process enables efficient production of synthetic quartz glass powder on an industrial scale.

Abstract: A quartz glass which would not become a source for the contamination even if it contains metallic impurities. This quartz glass includes a region where a concentration of E' center as measured by means of an electron spin resonance analysis is 3.times.10.sup.19 cm.sup.-3 or more. This quartz glass can be manufactured by a method including the steps of forming an initial quartz glass by melting and quenching a raw material for quartz glass, and implanting therein an ion, which is capable of entering into an SiO.sub.2 network of the initial quartz glass and substantially incapable of externally diffusing, to increase a concentration of E' center in at least part of the initial quartz glass. This quartz glass can be manufactured by a method making use of a quartz glass raw material containing 0.01 to 0.1% by weight of silicon, by a method of irradiating ultraviolet ray to the initial quartz glass, or by a method of giving an abrasion damage to the surface of the initial quartz glass by means of sand blast.

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: These glasses incorporate a combination of F and Al.sub.2 O.sub.3 to achieve even wider fluorescence and improved gain flatness. In addition, SPCVD incorporates large amounts of N into low-loss fiber whose high charge has an impact on rare earth behavior. The Surface Plasma Chemical Vapor Deposition (SPCVD) produces fiber preforms with high levels of F, Al.sub.2 O.sub.3, and N. These heavily fluorinated glasses provide much broader Er.sup.3+ emission than Type I or Type II silica for enhanced multichannel amplifiers. SPCVD successfully fluorinates silica with losses below 5 dB/km and increased Er.sup.3+ emission width.

Abstract: A synthetic quartz glass powder obtained by sol-gel method, wherein the number of black spot particles is at most 5 particles per 50 g, provides a high quality quartz glass shaped product with low bubble content when fused.

Abstract: A number of unique processes are disclosed for manufacture of sintered high-purity quartz glass products in which a shaped silica body or preform is made from an aqueous slurry of micronized silica particles by gel casting, slip casting or electrophoretic deposition. The silica particles may comprise a major portion by weight of crystalline silica. In one embodiment of the invention the sintered quartz glass is transparent, substantially bubble-free and suitable for scientific or optical uses. In another embodiment the porous silica preform is fired in steam to increase the hydroxyl content and then nitrided in a nitrogen-hydrogen reducing atmosphere. A minute amount of chemically-combined nitrogen in the high-purity quartz glass is sufficient to provide a tremendous improvement in physical properties and an incredible increase in the resistance to devitrification.

Abstract: The invention concerns a refractory material comprised essentially of vitreous or amorphous silica and presenting an improved resistance to corrosion by molten metals, principally aluminium. It contains at least 0.1% and no more than 10% by wt. of barium sulfate. It has a crystallized silica content of less than 10% and it is comprised of at least 75% vitreous or amorphous silica.

Abstract: Disclosed is a quartz glass product of enhanced opacity manufactured by fusion of silica particles, the opacity being enhanced by the reaction of an organosilicon additive in the course of the fusion process. A method of enhancing the opacity of a quart glass product by fusing silica particles in the presence of an organosilicon additive is also disclosed.

Abstract: A method is provided for the manufacture of SiO.sub.2 granular material. Silicic acid is dispersed in a liquid to form a dispersion. The dispersion is stirred in a stirring tank with formation of a homogeneous liquid phase. The homogeneous liquid phase is maintained by stirring at a substantially constant rate until the granular mass develops, when the solids content of the dispersion is within the range of 65 to 80 weight percent. Moisture is gradually extracted to form a granular mass which is dried and sintered.

Abstract: Opaque silica glass having a density of 2.0 to 2.18 g/cm.sup.3, sodium and potassium elements concentrations in the silica glass of each 0.5 ppm or less and an OH group concentration of 30 ppm or less, and containing bubbles which are independent bubbles having the following physical values: a bubble diameter of 300 .mu.m or less, and a bubble density of 100,000 to 1,000,000 bubbles/cm.sup.3, and a production process for opaque silica glass, including: filling quartz raw material grain having a particle size of 10 to 350 .mu.m in a heat resistant mold, heating it in a non-oxidizing atmosphere from a room temperature up to a temperature lower by 50 to 150.degree. C. than a temperature at which the above raw material grain is melted at a temperature-raising speed not exceeding 50.degree. C./minute, then, slowly heating it up to a temperature higher by 10 to 80.degree. C. than the temperature at which the quartz raw material grain is melted at the speed of 10.degree. C.

Abstract: Provided are high-purity quartz glass having a high purity, in particular, with little zirconium (Zr) and manufactured at low costs from natural quartz as the starting material and a method for the preparation thereof.

Abstract: Silica with the following physico-chemical properties:______________________________________ Specific surface m.sup.2 /g 80-400 Primary particle size nm 7-40 Tapped density g/l 50-300 pH value 3-10 Carbon content % 0.1-15 DBP number % <200 ______________________________________is produced by spraying a silica under intensive mixing, optionally with water or dilute acid at first and then with a surface-modifying reagent or a mixture of several surface-modifying reagents, then mixing, tempering, and subsequently destructuring/compressing and grinding.

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 nm 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: Fused silica boules (19) having improved off-axis homogeneity are produced by controlling the air flow around the boule (19) during its formation. The boule is formed in a containment vessel (13) which collects soot from a plurality of burners (14). The containment vessel (13) rotates and oscillates relative to the burners (14) as the boule (19) is formed. Surrounding the containment vessel (13) is an air flow wall (130) which oscillates with the containment vessel (13). The air flow wall (130) is spaced from the containment vessel (13) by a gap (175) through which air flows during boule formation. The dimensions of this gap (175) remain constant as the boule is formed. Surrounding the air flow wall (130) is a stationary wall (160). The stationary wall (160) is spaced from the air flow wall (130) by a gap (165) whose dimensions change as the boule is formed. A motion accommodating seal (155) blocks air flow in this gap (165).

Abstract: The invention provides an alternative to conventional sol-gel methods that utilize undesirably high amounts of a stabilizing agent such as TMAH and a gelling agent such as methyl formate. The method involves the steps of (a) providing a colloidal silica dispersion containing a stabilizing/gelling agent, where only a portion of the molecules of the agent ionize, and (b) subsequently adding to the silica dispersion a pH-reducing additive. The stabilizing/gelling agent has a dual function. The agent, e.g., an amine, initially acts as a stabilizer in the silica dispersion in that a portion of its molecules ionize, while an appreciable amount of the agent remains non-ionized. The agent later transforms in situ to a gelling agent upon addition of a pH-reducing additive. Specifically, as the pH-reducing additive lowers the pH to values at or around the pK.sub.

Abstract: A method for fabricating a silica glass is provided. The method includes the steps of adding silica and a dispersant to a premix solution obtained by dissolving an acrylic resin monomer and a cross-linking agent in distilled water, dispersing the mixed solution and adjusting the pH of the mixture, to form a sol. Air bubbles are removed from the sol, and then the resultant sol is aged. A polymerization initiator and a catalyst are added to the aged sol, and the pH of the reaction mixture is adjusted. The reaction mixture is poured into a mold, and then the mixture is gelated, aged, demolded, dried, and then thermally treated to remove organic substances. Hydroxy groups are eliminated and the gel is sintered. A high purity silica glass tube, substantially free of cracking after drying and having a low shrinking ratio can be obtained. Also, a large silica glass tube can be manufactured by this fabrication method.

Abstract: An opaque silica comprises silica and at least one second phase solid material. The at least one second phase solid material is essentially uniformly dispersed in the silica. A cut surface formed through the silica is free from surface defects since the at least one second phase solid material forms an opaque silica that is free from porosity.

Abstract: A method of producing a fused silica glass by thermally converting a polymethylsiloxane precursor, the lens transmitting ultraviolet radiation at wavelengths below 300 nm. without undergoing a marked absorption transition, the lens so produced, and a microlithography system employing a lens of such glass.

Abstract: A prefabricated part made of vitreous fused silica for use as a refractory, and in particular, for use in repairing coke ovens, which contains over 90% by weight of SiO.sub.2. The prefabricated part includes about 20 to 50% by weight of vitreous fused silica having 1 to 6 mm grain size, 20 to 40% by weight of vitreous fused silica having 0.1 to 1 mm grain size, 15 to 35% by weight of finely ground vitreous fused silica having grains less than 0.1 mm in size, 1 to 10% of finely ground vitreous fused silica having a specific surface area according to BET larger than 20 m.sup.2 per gram, 1 to 10% by weight of cement and 0.1 to 8% by weight of a phosphorous compound.

Abstract: A glass material variable in volume by irradiation with ultraviolet light has a GeO.sub.2 --SiO.sub.2 glass composition having a GeO.sub.2 content of 0.5 to 90 mol %, and is in the form of a thin film formed in an argon atmosphere or in an argon-oxygen mixed gas atmosphere by the high-frequency sputtering method.

Abstract: The electric incandescent lamp has a quartz glass lamp vessel (1) or envelope (4') around the lamp vessel, which has a red coloured dope in the area at the side of the incandescent body (3). The quartz glass with red dope contains samarium.sup.II oxide, aluminium oxide, titanium dioxide, and silicon dioxide, the analysis of the glass in its oxidized form being Sm.sub.2 O.sub.3 1 to 3% by weight, Al.sub.2 O.sub.3 up to 3% by weight, TiO.sub.2, rest SiO.sub.2, the molar ratio Al/Sm being at least about 2 and the molar ratio Sm/Ti being from 2 to 8.

Abstract: The process for producing a chemically prestressed glass of very high surface quality includes subjecting an Li.sub.2 O-free starting glass from the SiO.sub.2 -Al.sub.2 O.sub.3 -M.sub.2 O-MO system which also contains TiO.sub.2, CeO.sub.2 and F.sub.2 to chemical ion exchange by immersing it in a potassium salt bath at a temperature between 350.degree. C. and 550.degree. C. and at a residence time of between 0.5 and 20 hours to form the chemically prestressed glass. In a preferred embodiment of the process, the potassium salt bath contains a potassium nitrate melt and the glass is polished after prestressing. The chemically prestressed glass is particularly useful for making hard disks.

Abstract: Granules based on silicon dioxide and having the properties:Average particle size: 10 to 120 .mu.mBET surface area: 40 to 400 m.sup.2 /gPore volume: 0.5 to 2.5 ml/gPore size distribution: less than 5% of the total pore volume exists of pores with a diameter<5 nm, remainder are meso- and macroporespH value: 3.6 to 8.5Tapped density: 220 to 700 g/lThey are prepared by dispersing silicon dioxide in water, spray drying, and optionally heating and/or silanizing. The granules can be used as catalyst supports.

Abstract: A method for producing a SiO.sub.2 glass material having regions changed in light refractive index is provided which comprises implanting at least 5.times.10.sup.19 Ge ions/cm.sup.3 into a SiO.sub.2 glass substrate, heat-treating the substrate at a temperature exceeding 300.degree. C., and exposing the substrate to an ultraviolet light. Also provided is a SiO.sub.2 glass material produced by the method.

Abstract: A sodium containing lamp constructed to include of a fused quartz or fused silica arc chamber wherein the fused quartz and/or fused silica contains less than about 0.05 parts per million sodium. The arc chamber of the invention demonstrates a resistance to sodium diffusion resulting in a longer lived lamp with excellent color maintenance.

Abstract: A silica glass has a structure determination temperature of 1200 K or lower and a hydrogen molecule concentration of 1.times.10.sup.17 molecules/cm.sup.3 or more. The silica glass is used together with light in a wavelength region of 400 nm or shorter.

Abstract: Fused silica boules (19) having improved homogeneity are produced by causing the boule (19) to flow radially during its formation to achieve local mixing between portions of the boule which may have experienced different laydown conditions. The mixing is achieved by one or a combination of: (1) use of a containment vessel (13) having a gently sloping containment wall (22); (2) use of a containment vessel (13) whose inner radius (r.sub.v) is substantially larger than the outermost radius (r.sub.b) of the burners (14) used to produce the boule (19); and/or (3) maintaining the boule (19) at a sufficiently high temperature during laydown so that radial flow is achieved with a minimum head height of glass. Large blanks having high homogeneity can be made from such boules, e.g., blanks having diameters above 200 millimeters and .DELTA.n values of less than 0.25.times.10.sup.-6.

Abstract: Oscillation/rotation patterns for improving the off-axis homogeneity of fused silica boules are provided. The patterns reduce the optical effects of periodic off-axis striae by decreasing the ratio of .DELTA.n.sub.striae to .DELTA.z.sub.striae, where .DELTA.n.sub.striae is the average peak-to-valley magnitude of the striae and .DELTA.z.sub.striae is their average peak-to-peak period. The oscillation/rotation patterns have long repeat periods and cause soot-producing burners to trace out substantially spiral-shaped patterns on the surface of the boule.

Abstract: Soft quartz glass having low viscosity and a low thermal coefficient of expansion, high electrical insulation capability and free from release of contaminants, when used as a bulb of an incandescent lamp or as an envelope in an arc vessel of a discharge lamp, is a quartz glass made of ultra-pure quartz (SiO.sub.2), for example having a purity of 99.99 mol-%, doped with stoichiometric compounds of alkaline earth oxides with boron oxide, optionally also with a small quantity of Al.sub.2 O.sub.3 in an overall quantity of the doping substance of between about 0.05% to 0.8%, by weight.

Abstract: A fluorescent substance of which main component is comprised from 32 mol % to 35 mol % of silicon element and from 68 mol % to 65 mol % of oxygen element, and in which includes from 10 ppm to 1 wt % of silicon carbide and silicon nitride as an activator. And, a manufacturing method of the fluorescent substance by hydrolyzing silicon alkoxide by using alkali or acid catalyzer under the presence of carbon, and by heat treating the obtained precursor at the temperature of 500.degree. C. to 900.degree. C.

Abstract: The invention relates to the production of high purity fused silica glass which is highly resistant to optical damage by ultraviolet radiation in the laser wavelength of about 300 nm or shorter. In particular, this invention relates to a fused silica optical member or blank which exhibits substantially no optical damage up to 10.sup.7 pulses (350 mJ/cm.sup.2) at the KrF laser wavelength region of about 248 nm, and at the ArF laser wavelength region of about 193 nm.

Abstract: Pure transparent quartz glass is provided by molding powdery amorphous silica into an article, converting the molded powdery amorphous silica into crystalline silica of high-temperature type cristobalite structure, and then fusing the crystalline silica, the quartz glass containing impurities respectively at a content of not higher than 1 ppm, and an OH group at a content of not higher than 20 ppm, and having a viscosity of 10.sup.12.0 poise or more at 1200.degree. C. The quartz glass is transparent and has high purity, and is excellent in high temperature viscosity characteristics. The quartz glass can be produced at a low cost.

Abstract: A novel copper activated thermoluminescence dosimeter comprising a glass composition having: about 94-97 weight percent SiO.sub.2 ; about 0.4 to 2 weight percent Al.sub.2 O.sub.3 ; about 0.02 to 1 weight percent M.sub.2 O, where M comprises Na.sup.+ or K.sup.+ ; about 2 to 6 weight percent B.sub.2 O.sub.3 ; and Cu(I), where Cu(I) is present at a level between about 10.sup.18 to 10.sup.19 ions/cm.sup.3 ; method of making the same.

Abstract: A glass composition, particularly well suited for use in constructing sodium containing lamp envelopes. The glass composition is comprised of silica doped with yttrium and/or cesium, preferably in combination aluminum.

Abstract: A novel copper activated thermoluminescence dosimeter comprising a glass composition having: about 94-97 weight percent SiO.sub.2 ; about 0.4 to 2 weight percent Al.sub.2 O.sub.3 ; about 0.02 to 1 weight percent M.sub.2 O, where M comprises Na.sup.+ or K.sup.+ ; about 2 to 6 weight percent B.sub.2 O.sub.3 ; and Cu(I), where Cu(I) is present at a level between about 10.sup.18 to 10.sup.19 ions/cm.sup.3 ; method of making the same.

Abstract: The use of a composition based on silicon dioxide as antiblocking agent is described which is characterized in that it has silicon dioxide having a particle size of 2 to 8 .mu.m, a specific surface of 150 to 850 m.sup.2 /g and a specific pore volume of 1.4 to 2.0 ml/g which has been treated with polyol. This silicon dioxide can be used together with a slip agent as combined antiblocking agent and slip agent. The working-in of the antiblocking agent or of the combined antiblocking agent and slip agent into a polymer is preferably in the form of a masterbatch. A preferred antiblocking agent contains as polyol ethoxylated pentaerythritol in which the pentaerythritol/ethoxy ratio lies in the range from 1:0.5 to 1:25. The antiblocking agent can be obtained by micronizing silicon dioxide to the given particle size and impregnating it with the polyol.

Abstract: High silica glasses exhibiting blue color by transmitted light are produced by impregnating a porous, high silica glass with a solution of cobalt, aluminum, and selected alkaline earth or alkali salts, and then consolidating the glass under oxidizing conditions to dope the glass with the corresponding oxides. The tinted glass has particular utility as a blue filter for lighting applications.

Abstract: A synthetic silica glass powder obtained by calcining a silica gel powder obtained by hydrolysis of a tetraalkoxysilane, said synthetic silica glass powder containing from 1.times.10.sup.-1 to 1.times.10.sup.-4 ppm of boron and having an internal silanol group concentration of at most 150 ppm and an isolated silanol group concentration of at most 5 ppm.