Abstract: Fused silica articles exhibiting improved internal transmission and decreased absorption change when irradiated with a laser when compared with fused silica articles containing lower levels of aluminum. The articles also exhibit induced transmission when irradiated with a laser. The articles also exhibit improved off-axis refractive index homogeneity.

Abstract: The present invention is a process for modifying the properties of a porous freeform fabricated part by increasing its density and reducing its porosity. The porosity and density of a freeform fabricated part are altered by packing the pores in a freeform part with an infiltrant, such as a preceramic polymer. The process includes drawing a vacuum on or pressurizing the freeform part while it is in an infiltrant bath, thereby forcing the infiltrant into the pores of the freeform part. After removing the densified freeform part from the infiltrant bath, the freeform part is subjected to a treating process, such that the infiltrant within the pores transforms to a ceramic or ceramic-containing phase to thereby increasing the density of the freeform part.

Abstract: An infrared absorption filter consisting of 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide than CuO or CdO is provided. A process of fabricating an infrared absorption filter is also provided. The process comprises introducing a divalent copper compound and a compound of a metal species acting as a network modifier oxide in the form of metal ions into a wet gel. The wet gel can be dipped in a dipping solution to precipitate the divalent copper compound and the compound of a metal species acting as the network modifier oxide in the wet gel. The wet gel can be dried and heated, thereby obtaining an infrared absorption glass. The infrared absorption glass can be cut and polished, thereby fabricating a filter.

Abstract: The present invention relates to a quartz glass blank for an optical component for transmission of ultraviolet radiation of a wavelength of 250 nm or shorter, and to a use of the quartz glass blank in microlithography in combination with ultraviolet radiation of a wavelength of 250 nm or shorter. Moreover, the invention relates to a procedure for manufacture of the quartz glass blank. A quartz glass blank of the described type should show little induced absorption and be optimized with respect to compaction and decompaction.

Abstract: The present invention concerns a quartz glass blank for an optical component for the transmission of ultraviolet radiation of a wave length of 250 nm and under, as well as its utilization in microlilthography in connection with ultraviolet radiation of a wavelength of 250 nm and under. Such quartz glass blank is to have low induced absorption, while being optimized in respect of compaction and de-compaction.

Abstract: Fused silica articles containing at least 50 ppb aluminum are disclosed. The fused silica articles containing these levels of aluminum exhibit improved internal transmission and decreased absorption change when irradiated with a laser when compared with fused silica articles containing lower levels of aluminum.

Abstract: Fused silica articles exhibiting improved internal transmission and decreased absorption change when irradiated with a laser when compared with fused silica articles containing lower levels of aluminum. The articles also exhibit induced transmission when irradiated with a laser.

Abstract: A high temperature oxidation resistant coating performs a self-repairing function of self-repairing the cracks under a heated environment and has low catalytic properties. The high temperature oxidation resistant coating is prepared by dispersing silicate particles containing a composite oxide consisting of an oxide of a lanthanoide series rare earth element including yttrium and silicon oxide into a glass-based matrix.

Abstract: A synthetic quartz glass to be used for light with a wavelength of from 150 to 200 nm, wherein the OH group concentration is at most 100 ppm, the hydrogen molecule concentration is at most 1×1017 molecules/cm3, reduction type defects are at most 1×1015 defects/cm3, and the relation between &Dgr;k163 and &Dgr;k190, as between before and after irradiation of ultraviolet rays, satisfies 0<&Dgr;k163<&Dgr;k190, and a process for its production.

Abstract: A process for producing an SiO2 shaped body which is vitrified in a partial region or completely, in which process an amorphous, porous SiO2 preform is sintered or vitrified by contactless heating by means of laser radiation, by means of which contamination of the SiO2 shaped body with foreign atoms is avoided.

Abstract: Fluorine-containing glass which comprises silica and contains, in said silica, not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, said fluorine-containing glass having a concentration ratio of F/Cl of 100 or more. Also disclosed is fluorine-containing glass which contains not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, and has a concentration ratio of F/Cl of 1000 or more.

Abstract: A process for producing a synthetic quartz glass for an optical member, which comprises a step of irradiating a synthetic quartz glass having an OH group content of 50 ppm or lower with vacuum ultraviolet light having a wavelength of 180 nm or shorter to improve the transmittance in a region of wavelengths of not longer than 165 nm.

Abstract: Fused silica members having high internal transmission and low birefringence are disclosed. Methods of making such fused silica members are also disclosed. According to the present invention, fused silica members having an internal transmission equal to or greater than 99.65%/cm at 193 nm and having an absolute maximum birefringence along the use axis of less than or equal to 0.75 nm/cm are provided.

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: Highly durable silica glass containing 0.01% to 2% by weight of at least one element selected from magnesium, calcium, strontium, barium, yttrium, hafnium and zirconium. The silica glass is produced by melting a powdery material comprising a finely divided silica powder and a finely divided zirconium-containing substance by oxyhydrogen flame or plasma arc to form an accumulated molten material layer, and extending the molten material layer outwardly in radial directions.

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 method for manufacturing a photomask material includes delivering a powder containing silicon dioxide into a plasma to produce silica particles and depositing the silica particles on a deposition surface to form glass.

Abstract: In the light of the disadvantages of the prior art technology, an object of the present invention is to provide a method for producing a synthetic quartz glass member for excimer lasers, which comprises, while suppressing the generation of reductive defects which impairs the resistance against laser radiations, incorporating a sufficient amount of hydrogen molecules capable of achieving a high resistance against laser radiation into the quartz glass, yet uniformly incorporating the hydrogen molecules to realize a flat distribution in refractive indices attributed to the distribution in the density of hydrogen molecules. It is also an object of the present invention to provide a synthetic quartz glass member for excimer lasers obtained by the production method above, which yields high resistance against laser radiations and homogeneity.

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 contains doped O2 molecules and which exhibits very high transmittance and laser transmission durability in the vacuum ultraviolet (VUV) wavelength region. 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 contains intersticial O2 molecules which provide improved endurance to laser exposure. Preferably the O2 doped silicon oxyfluoride glass is characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: According to one aspect of the present invention an optically active glass contains Sb2O3, up to about 4 mole % of an oxide of a rare earth element, and 0-20 mole % of a metal halide selected from the group consisting of a metal fluoride, a metal bromide, a metal chloride, and mixtures thereof, wherein this metal is a trivalent metal, a divalent metal, a monovalent metal, and mixtures thereof. In addition, any of the glass compositions described herein may contain up to 15 mole % B2O3 substituted for an equivalent amount of Sb2O3.

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 composite material has a quartz glass phase and a complex compound phase compounded with the quartz glass phase, which is made of one or more compounds selected from a group of silicon carbide, silicon nitride, silicon, titanium nitride and titanium carbide, as a main ingredient. The composite material can be used instead of quartz glass, and can prevent the generations of microcrack, tipping and particles after the mechanical working.

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 with the silicon oxyfluoride glass having a preferred fluorine content<0.5 weight percent. 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 method for the production of silicon oxide particles includes the pyrolysis of a molecular stream with a silicon compound precursor, an oxygen source and a radiation absorbing gas. The pyrolysis is driven by a light beam such as an infrared laser beam. The method can be used in the production of nanoscale particles including highly uniform nanoscale particles.

Abstract: An object of the present invention is to provide a synthetic quartz glass optical material having a high optical transmittance for a radiation 157 nm in wavelength emitted from F2 excimer laser and a high resistance against irradiation of a F2 excimer laser radiation, yet having a uniformity suitable for such a fine patterning using a F2 excimer laser, and to provide an optical member using the same.

Abstract: The invention provides coated optical lithography elements and methods of coating optical elements, and particularly optical photolithography elements for use in below 240 nm optical photolithography systems utilizing vacuum ultraviolet light (VUV) lithography wavelengths no greater than about 193 nm, such as VUV projection lithography systems utilizing wavelengths in the 193 nm or 157 nm region. The optical devices manipulate vacuum ultraviolet lithography light less than 250 nm utilizing a deposited silicon oxyfluoride film. The deposited silicon oxyfluoride optical coating assists in the manipulation of incident light and protects the underlying optical materials, layers, and surfaces.

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 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 discharge lamp comprising an arc tube containing a pair of electrodes in a light-emitting portion and an outer tube that envelops the light-emitting portion and is at least partly fused to the arc tube, wherein the outer tube comprises silicon dioxide in the range from 90 to 99.88 wt. % and boron in the range from 0.12 wt. % or more. The discharge lamp can inhibit the arc tube from deforming when the outer tube and arc tube are fused to each other by adjusting a softening temperature of the outer tube to an appropriate temperature and can realize a high accuracy of luminous intensity distribution.

Abstract: The invention relates to a synthetic quartz glass preform which is produced according to the flame hydrolysis technique with subsequent cooling and is suitable for the application of high-energy DUV radiation in the wave length range under 250 nm. Said preform has a core area which contains ≧1150 ppm OH, a strain double refraction of ≦5 nm/cm and a resistance to high-energy DUV radiation as a result of a transmission reduction of &Dgr; T ≦0.1 %/cm thickness. The quartz glass has been exposed to the following radiation: wavelength &lgr;1=248 nm, laser shot frequency ≧300 Hz, laser shot value ≧109 and rumination ≦10 mJ/cm2, and wavelength &lgr;2=193 nm, laser shot frequency ≧300 Hz, laser shot value ≧109 and rumination ≦5 mJ/cm2. A device for producing said preform comprises a horizontally positioned muffle with two different-sized openings facing each other. The larger of said openings is for removing the preform, the smaller opening being for introducing a burner.

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.

Abstract: A glass consisting essentially of antimony oxide. An optically active glass consisting essentially of antimony oxide and up to about 4 mole % of an oxide of a rare earth element. A rare earth-doped, antimony oxide-containing glass including 0-99 mole % SiO2, 0-99 mole % GeO2, 0-75 mole % (Al, Ga)2O3, 0.5-99 mole % Sb2O3, and up to about 4 mole % of an oxide of a rare earth element. The oxide of the rare earth element may comprise Er2O3. The glass of the invention further includes fluorine, expressed as a metal fluoride. An optical energy-producing or light-amplifying device, in particular, an optical amplifier, comprising the above-described glass. The optical amplifier can be either a fiber amplifier or a planar amplifier, either of which may have a hybrid composition. Embodiments of the glass of the invention can be formed by conventional glass making techniques, while some of the high content antimony oxide embodiments are formed by splat or roller quenching.

Abstract: Lithographic methods are disclosed. In one such method, a pulsed ultraviolet radiation source for producing ultraviolet lithography radiation having a wavelength shorter than about 300 nm at a fluence of less than 10 mJ/cm2/pulse and a high purity fused silica lithography glass having a concentration of molecular hydrogen of between about 0.02×1018 molecules/cm3 and about 0.18×1018 molecules/cm3 are provided. A lithography pattern is formed with the ultraviolet lithography radiation; the lithography pattern is reduced to produce a reduced lithography pattern; and the reduced lithography pattern is projected onto a ultraviolet radiation sensitive lithography medium to form a printed lithography pattern. At least one of the forming, reducing, and projecting steps includes transmitting the ultraviolet lithography radiation through the high purity fused silica lithography glass. Lithography systems and high purity fused silica lithography glass are also described.

Abstract: An optical member includes a fused silica glass having a concentration of ≡SiH moiety below detection limit as measured by Raman spectroscopy and a concentration of molecular hydrogen of at least 1×1017 molecules/cm3. The fused silica glass exhibits an induced absorption level which quickly attains an initial peak upon exposure to irradiation and rapidly decays to a low value. The induced absorption level after decaying to the low value remains substantially unchanged by further irradiation.

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 3×1019 cm−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 SiO2 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 low-viscosity dental material contains a non-settling nanoscale filler. Improvements of the mechanical properties of the dental materials, including the abrasive resistance and the compressive strength are provided. Furthermore, the dental materials have increased resistance to microleakage and have increased bond strengths. The filler forms a stable sol with low-viscosity dental materials and the filler may be prepared by surface treatment of fillers having a primary particle size of from about 1 to about 100 nanometers.

Abstract: A modified silica glass composition for providing a reduction in the multiphonon quenching for a rare-earth dopant comprising:

Abstract: A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: There is disclosed second-order nonlinear glass material wherein a part having second-order nonlinearity contain Ge, H and OH and second-order nonlinear optical constant d of 1 pm/V or more, and a method for producing second-order nonliner glass material comprising treating a porous class material containing Ge with hydrohen, sintering it and subjecting it to a ultraviolet poling treatment. There can be provided second-order nonlinger glass material having second-order nonlinearity which is a sufficiently high and has a sufficiently long lifetime for a practical purpose, in use of the glass material for optical elements or the like.

Abstract: In a known process for the production of opaque quartz glass a blank is formed from synthetic SiO2 granulate and is heated at a vitrification temperature to form a body of opaque quartz glass. In order to provide on this basis a process for the production of pure opaque quartz glass with a homogenous pore distribution, high density, high viscosity and a low tendency to devitrify, it is proposed according to the invention that the SiO2 granulate to be used is a SiO2 granulate (21; 31) composed of at least partially porous agglomerates of SiO2 primary particles, with a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.8 g/cm3. A SiO2 granulate (21; 31) suitable for the implementation of the process is distinguished in that it is formed from at least partially porous agglomerates of SiO2 primary particles and in that it has a specific BET surface ranging from 1.5 m2/g to 40 m2/g and an apparent density of at least 0.6 g/cm3.

Abstract: A synthetic silica glass having a high transmittance for vacuum ultraviolet rays, for example F2 excimer laser beam with a wavelength of 157 nm, a high uniformity and a high durability and useful for ultraviolet ray-transparent optical glass materials is produced from a high-purity silicon compound, for example silicon tetrachloride, by heat treating an accumulated porous silica material at a temperature not high enough to convert the porous silica material to a transparent silica glass in an inert gas atmosphere for a time sufficient to cause the OH groups to be condensed and removed from the glass, and exhibits substantially no content of impurities other than OH group a difference between highest and lowest fictional temperatures of 50° C.

Abstract: In a projection optical system having at least two silica glass optical members, a birefringence value is measured at each of points in a plane normal to the optical axis with the center at an intersection of each optical member with the optical axis, a distribution of signed birefringence values in each optical member is obtained by assigning a positive sign to each birefringence value when a direction of the fast axis thereof is a radial direction to the intersection with the optical axis and assigning a negative sign to each birefringence value when the direction of the fast axis thereof is normal to the radial direction, and the optical members are combined with each other so as to satisfy such a placement condition that a signed birefringence characteristic value of the entire projection optical system calculated based on the distributions of signed birefringence values is between −0.5 and +0.5 nm/cm both inclusive.

Abstract: Fluorine-containing glass which comprises silica and contains, in said silica, not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, said fluorine-containing glass having a concentration ratio of F/Cl of 100 or more. Also disclosed is fluorine-containing glass which contains not more than 10 ppm of OH group, not more than 10 ppm of Cl and not less than 1000 ppm of F, and has a concentration ratio of F/Cl of 1000 or more.

Abstract: The application discloses a number of unique sintered quartz glass products together with new silica compositions and processes for making and using such products. Nitrided clear and opaque nitrided quartz products are disclosed having incredible physical properties resulting from the incorporation of very small, but effective, amounts (e.g., 25 ppm or more) of chemically bound nitrogen. Opaque quartz glass heat shields with remarkable resistance to transmission of infrared radiation are disclosed which can have a high bubble population density, such as 80 to 120 per mm2. These heat shields make possible remarkable improvement in the performance of tube furnaces and other reactors used in processing silicon wafers and other electronic components.

Abstract: The invention relates to a glass excellent in infrared absorption capability and corrosion resistance, and its fabrication process. A compound of divalent copper and a compound of a metal species for a network modifier oxide are introduced in a wet gel. Then, the wet gel is dipped in a dipping solution having a low solubility with respect to the compound of divalent copper and the compound of a metal species for a network modifier oxide for the precipitation in the wet gel of the divalent-t copper compound and the compound of a metal species for a network modifier oxide, followed by drying and firing. Thus, an infrared absorbing glass comprising 70 to 98 mol % of SiO2, 1 to 12 mol % of CuO and 1 to 18 mol % of a network modifier oxide other than CuO is fabricated.

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 process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.

Abstract: There is disclosed a synthetic fused silica member used at a wavelength of 200 nm or less which has a hydroxyl group-content of 1 to 50 ppm and a fluorine-content of 100 to 1000 ppm, and contains no chlorine, and has a birefringence of the synthetic fused silica member of 2 nm/cm or less. The synthetic fused silica member can be used as a synthetic fused silica substrate for photomask, or in an optical system wherein a fluorine excimer laser is used as a light source. There can be provided a synthetic fused silica member which can efficiently transmit a light having a wavelength as 200 nm or less, especially fluorine excimer laser (157 nm), and does not suffer from lowering of transmittance due to damage.

Abstract: Fused silica stepper lens for photolithographic application are disclosed which are resistant to laser-induced damage, specifically, compaction or densification which can lead to an increase in the optical path length of the lens. The figure compares the phase front distortions of a standard fused silica with the phase front distortions observed in two inventive stepper lens fused silica.

Abstract: 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/cm2 to about 20 slm/cm2. 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.