Abstract: A reforming process of a quartz glass crucible in which the quartz glass crucible is reformed by an arc discharge generated by electrodes positioned around a rotational axis and configured to heat an inside surface of the crucible while the crucible is rotated. The process includes arranging electrodes in an electrode structure such that neighboring electrodes are positioned at regular intervals in a ring-like configuration; forming a stable ring-like arc between the neighboring electrodes, without generating a continuous arc between electrodes facing each other across a central portion of the ring-like configuration; heating the inside surface of the crucible; and removing a foreign substance located on the inside surface of the crucible or a bubble located under the inside surface of the crucible.

Abstract: A method of producing a foamed glass composite panel is provided. Glass and 0.1-20.0% by weight of at least one non-sulfur based foaming agent are mixed together, and the mixture is heated to a temperature sufficient to foam it. The foamed mixture is cooled to form at least one foamed glass substrate. During or after the cooling step, material is bonded or attached to at least one side of the foamed glass substrate to form a composite panel.

Abstract: A process for producing synthetic quartz glass using a burner composed of a plurality of concentric nozzles involves the steps of feeding a silica-forming raw material gas and a fluorine compound gas to a reaction zone from a center nozzle, feeding oxygen gas from a second nozzle outside the center nozzle, and feeding oxygen gas and/or hydrogen gas from a third nozzle. The silica-forming raw material gas is hydrolyzed to form fine particles of silica, which particles are deposited on a rotatable substrate so as to form a porous silica matrix, which is then fused to give the quartz glass. The flow rate of the oxygen gas fed from the second nozzle and the flow rate of the raw material gas are controlled so as to provide a 1.1- to 3.5-fold stoichiometric excess of oxygen. The excess oxygen suppresses Si—Si bond formation in the quartz glass, enabling the production of synthetic quartz glass having a high transmittance in the vacuum ultraviolet region.

Abstract: A process for manufacture of a component made of opaque synthetic quartz glass, and a quartz glass tube manufactured according to said process. The process comprises (i) providing a starting material in the form of granulated material of highly pure, synthetic SiO2 comprising at least partially porous agglomerates of SiO2 primary particles, the granulated material having a compacted bulk density of no less than 0.8 g/cm3, (ii) filling the granulated material into a mold and converting it to an opaque quartz glass preform through a process of melting, and (iii) reshaping the preform in a heat reshaping process to obtain a component made of opaque quartz glass. A quartz glass tube is made of quartz glass consisting of a granulated material of synthetic SiO2 with a lithium content of no more than 100 wt-ppb, and the wall thickness of said component being in the range of 0.5 mm to 15 mm.

Abstract: A method of forming a glass sheet includes obtaining a preform generated from a glass composition and conveying the preform through a channel having a temperature that decreases along a length of the channel to form a glass sheet having a predetermined width and thickness.

Abstract: Methods and apparatus for manufacturing titania-containing fused silica bodies are disclosed. The titania-containing fused silica bodies are subsequently processed to make extreme ultraviolet soft x-ray masks. The methods and apparatus involve providing powders external to a furnace cavity and depositing the powders in the furnace cavity to form a titania-containing fused silica body.

Abstract: A method for producing a silica glass body having a low bubble content includes melting silica sand in a chamber (62) of a rotating furnace housing (20) to form molten silica. Helium-containing gas is fed into the chamber, both during introduction of the sand and during the heating step. The helium diffuses more readily from the molten silica than other gases, resulting in lower bubble content. The furnace is heated by establishing a gas plasma arc (60) between spaced electrodes (64, 66) within the chamber.

Abstract: A method for forming EUV LITHOGRAPHY GLASS STRUCTURES WITH VOIDS is disclosed which includes forming a slurry mixture including silica soot particles, and inserting the slurry mixture into a casting mold. The method provides low weight mass reduced rigid glass structures with beneficial thermal stability. The casting mold includes therein a casting form. The casting form is adapted to provide selected geometry void spaces within the glass lithography structure. The slurry mixture is dried to form a green ware object. The casting form is removed from the green ware and the green ware object is consolidated into a lithography glass structure with voids.

Abstract: A method for forming EUV Lithography straie-free glass structures is disclosed which includes forming a mixture of silica soot. The homogenized mixture is extruded into a flat planar pre-form, and the extruded pre-form is then consolidated by, heating into a substantially full density, substantially striae-free lithography glass substrate structure.

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: Methods and apparatus for adding metals such as aluminum to fused silica glass articles are disclosed. The methods and apparatus allow for controlled, low level addition of metals into fused silica glass articles. The fused silica glass articles containing added aluminum exhibit improved internal transmission and decreased absorption change when irradiated with a laser.

Abstract: The present invention is directed to a method for producing optical blanks for EUV microlithographic components. The method includes the step of providing soot particles and spray-drying the soot particles to form an agglomerate. The agglomerate is dry-pressed to form a green body. The green body is heated to form a glass object. The method of the present invention produces optical components having substantially no striae. Further, the method of the present invention produces optical blanks having substantially no low frequency thickness variation. As a result, scattering is substantially reduced when EUV light is reflected from a component produced from the optical blank.

Abstract: High-strength sinterable lithium disilicate glass ceramics are described which can be further processed in particular by pressing in the viscous state to shaped dental products.

Abstract: A method for producing ultra-high purity, optical quality, glass articles is disclosed which involves:

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 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: 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 silica glass member for semiconductor in which each concentration of Fe, Cu, Cr and Ni is 5 ppb or less and the concentration of an OH group is 30 ppm or less and which has a viscosity of 1013.0 poise or more at 1200° C. is provided as a silica glass member for semiconductor having high heat-resistance and higher purity.

Abstract: The invention concerns a quartz glass body for an optical component for the transmission of UV radiation with a wavelength of 250 nm and less, especially for a wavelength of 157 nm, as well as a process for the manufacture of the quartz glass body where fine quartz glass particles are formed by flame hydrolysis of a silicon compound, deposited and vitrified. Suitability of a quartz glass as represented by high base transmission and radiation resistance depends on structural properties caused by local stoichiometric deviations, and on the chemical composition. The quartz glass body according to the inventions is distinguished by a uniform base transmission (relative change of base transmission ≦1%) in the wavelength range from 155 nm to 250 nm (radiation penetration depth of 10 mm) of at least 80%, a low OH content (less than 10 ppm by weight) and a glass structure substantially free from oxygen defect centers.

Abstract: In order to provide a quartz glass crucible distinguished by high purity, high opacity and/or low transmissibility in the IR spectrum, it is proposed on the basis of a known quartz glass crucible of opaque quartz glass with a crucible body symmetrical in relation to a rotational axis, an outer zone (3) of opaque quartz glass transitioning radially toward the inside into an inner zone (2) of transparent quartz glass and with a density of at least 2.15 g/cm3, that according to the invention, the crucible body (1) be made of a synthetic SiO2 granulate with a specific BET surface ranging from 0.5 m2/g to 40 m2/g, a tamped volume of at least 0.8 g/cm3 and produced from at least partially porous agglomerates of SiO2 primary particles.

Abstract: Silica crucibles containing an inner layer which is substantially pure and substantially bubble-free and methods for making such crucibles. The inner layer is also substantially stable against roughening and spot devitrification. The inner layer is formed by making a web structure which is then converted to a continuous layer, thereby minimizing or eliminating bubble formation. The inner layer is also formed using a gettering agent which getters alkaline and alkaline-earth elements while the inner layer is formed. The alkaline and alkaline-earth elements are gettered on an innermost portion of the inner layer which is later removed, leaving an inner layer with relatively few impurities. When used in a CZ-crystal growing process, the inner surface of the crucible remains smooth and substantially no bubbles grow in the inner layer.

Abstract: This invention relates to a method of rendering fused silica resistant to compaction caused by UV laser beam irradiation. The method of the invention results is a fused silica member that is desensitized to compaction caused by the long-term exposure to UV laser beams. The invention includes a means to pre-compact fused silica members using high energy radiation.

Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: The method comprises a preheating step to heat a metal base 10 entirely, a pre-spraying step to for a glass pre-coating 13 by pre-spraying a glass material onto the surface of the preheated base, a main-spraying step to form a glass coating 14 by additionally heating the glass pre-coating formed in the previous step and main-spraying a like glass material onto the surface.

Abstract: A method for producing a fused silica glass containing titania includes synthesizing particles of silica and titania by delivering a mixture of a silica precursor and a titania precursor to a burner, growing a porous preform by successively depositing the particles on a deposition surface while rotating and translating the deposition surface relative to the burner, and consolidating the porous preform into a dense glass.

Abstract: A method for forming a fused silica glass includes delivering a silica precursor to a burner and passing the silica precursor through the flame of the burner to form silica particles, depositing the silica particles on a planar surface to form a flat, porous preform, dehydrating the porous preform, and consolidating the porous preform into a flat, dense glass.

Abstract: A process for manufacture of a component made of opaque synthetic quartz glass, and a quartz glass tube manufactured according to said process. The process comprises (i) providing a starting material in the form of granulated material of highly pure, synthetic SiO2 comprising at least partially porous agglomerates of SiO2 primary particles, the granulated material having a compacted bulk density of no less than 0.8 g/cm3, (ii) filling the granulated material into a mold and converting it to an opaque quartz glass preform through a process of melting, and (iii) reshaping the preform in a heat reshaping process to obtain a component made of opaque quartz glass. A quartz glass tube is made of quartz glass consisting of a granulated material of synthetic SiO2 with a lithium content of no more than 100 wt-ppb, and the wall thickness of said component being in the range of 0.5 mm to 15 mm.

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 new method is disclosed for producing thin plates by sintering a thin gel plate (e.g., silica) made using a sol-gel process, which substantially eliminates warpage of the plate during the sintering step. Sintering a sol-gel based silica plate to a dense glass typically causes significant shrinkage, and this can cause the plate to curl, especially around its edges. This phenomenon is referred to as warpage. In the method of the invention, the sintering step is performed while the gel plate is mounted on a support surface, separated by a thin layer of refractory powder. At the high sintering temperature, the powder partially fuses and sticks to both the gel plate and the support surface, which prevents non-uniform stresses in the gel plate from warping the plate.

Abstract: The invention provides optical projection lithography methods, photolithography photomasks, and optical photolithography mask blanks for use in optical photolithography systems utilizing deep ultraviolet light (DUV) wavelengths below 300 nm, such as DUV projection lithography systems utilizing wavelengths in the 248 nm region and the 193 nm region. The invention provides improved production of lithography patterns by inhibiting polarization mode dispersion of lithography light utilizing low birefringence mask blanks and photomasks.

Abstract: Fluorine-containing synthetic quartz glass is produced by feeding silica-forming material, hydrogen, and oxygen gases from a burner to a reaction zone, flame hydrolyzing the silica-forming material in the reaction zone to form particles of silica, depositing the silica particles on a rotatable substrate in the reaction zone to form a porous silica matrix, and heating and vitrifying the porous silica matrix in a fluorine compound gas-containing atmosphere. During formation of the porous silica matrix, the angle between the center axes of the silica matrix and the silica-forming reactant flame from the burner is adjusted to 90-120° so that the porous silica matrix has a density of 0.1-1.0 g/cm3 with a narrow distribution within 0.1 g/cm3. The resulting quartz glass has a high transmittance to light in the vacuum ultraviolet region below 200 nm.

Abstract: An assembly of rib structures sandwiched between a dielectric glass layer and a glass substrate for use in a flat panel display, such as plasma addressed liquid crystal (PALC) displays, is formed by a number of methods. One method includes molding thermoplastic glass frit containing paste into rib structures, transferring the rib structures to a thin transparent layer of a thermoplastic dielectric glass frit containing composition on a drum, and transferring the rib structures with the thin transparent dielectric glass layer to a glass substrate having metallic electrodes already formed thereon.

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: SiO2—TiO2 glasses having a low coefficient of thermal expansion are produced by a molding being produced that consists of SiO2 powder, SiO2—TiO2 powder or TiO2 powder and that contains by way of secondary component a titanium-containing component which is converted into amorphous TiO2.

Abstract: High purity direct deposit vitrified 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 direct deposit vitrified 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 direct deposit vitrified 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 direct deposit vitrified 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 raw material mixture, which has a glass composition containing a salt or an oxide of a flame reaction metal, is heated, and an intermediate base material, in which the salt of the flame reaction metal, or the like, has been thermally decomposed and which is in a temporary sintered state or a fused glass state, is thereby formed. The intermediate base material is ground, and a ground material is thereby obtained. The ground material is mixed together with a liquid and, optionally, a binder, and a viscous flame reaction material is thereby formed. The viscous flame reaction material is supported on a substrate and heated to a temperature, which is not lower than a vitrification melting temperature of the viscous flame reaction material. In this manner, the flame reaction material is fusion bonded to the substrate. Generation of a thermal decomposition gas in the baking step is thus restricted, and the carrying of the flame reaction material on the substrate is carried out appropriately.

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: A process for producing synthetic quartz glass using a burner composed of a plurality of concentric nozzles involves the steps of feeding a silica-forming raw material gas and a fluorine compound gas to a reaction zone from a center nozzle, feeding oxygen gas from a second nozzle outside the center nozzle, and feeding oxygen gas and/or hydrogen gas from a third nozzle. The silica-forming raw material gas is hydrolyzed to form fine particles of silica, which particles are deposited on a rotatable substrate so as to form a porous silica matrix, which is then fused to give the quartz glass. The flow rate of the oxygen gas fed from the second nozzle and the flow rate of the raw material gas are controlled so as to provide a 1.1- to 3.5-fold stoichiometric excess of oxygen. The excess oxygen suppresses Si—Si bond formation in the quartz glass, enabling the production of synthetic quartz glass having a high transmittance in the vacuum ultraviolet region.

Abstract: This invention relates to a method of rendering fused silica resistant to compaction caused by UV laser beam irradiation. The method of the invention results is a fused silica member that is desensitized to compaction caused by the long-term exposure to UV laser beams. The invention includes a means to pre-compact fused silica members using high energy radiation.

Abstract: Disclosed is a method of making a photonic crystal using a combination of extruding and drawing techniques. The method is contemplated as being capable of producing both two and three dimensional crystals due to the maturity and diversity of extruding and drawing technology. The method allows the drawing of relatively large photonic crystals and is flexible enough to provide a periodic array of channels or filaments as the crystal features. After the extruding step or steps and before the step of heating and drawing, a plurality of elongated extruded bodies can be bundled and drawn as a unit.

Abstract: A method of rendering fused silica resistant to compaction caused by UV laser beam irradiation. The method of the invention results in a fused silica member that is desensitized to compaction caused by the long-term exposure to UV laser beams. The invention includes a means to pre-compact fused silica members using high energy radiation.

Abstract: A method for producing a silica glass for photolithography, which comprises the following steps: jetting a starting material gas, an oxygen gas and a hydrogen gas from a burner and depositing and consolidating silica glass powder on a target to form an ingot having a growing direction, where the ingot is grown in such a manner that at least a part of glass synthesis face on the ingot having the silica glass powder deposited and consolidated is a plane substantially perpendicular to the growing direction of the ingot, thereby to obtain the ingot having a portion in which striae are substantially perpendicular to the growing direction of the ingot; and cutting out of the ingot the portion in which the striae are substantially perpendicular to the growing direction of the ingot, thereby to obtain a silica glass having striae which are substantially parallel to each other and are planar.