Abstract: A known method for producing synthetic quartz glass comprises: (a) reacting a carbonic silicon compound-containing raw material with oxygen in a reaction zone into SiO2 particles, (b) precipitating the SiO2 particles on a sedimentation area by forming a porous SiO2 soot body containing hydrogen and hydroxyl groups, (c) drying the porous SiO2 soot body, and (d) glazing to the synthetic quartz glass by heating the soot body up to a glazing temperature. In order to facilitate cost-efficient production of quartz glass by means of pyrolysing or hydrolysing a carbon-containing silicon compound using a carbon-containing raw material, the invention describes the production of a soot body with a carbon content within the range of 1 ppm by weight to 50 ppm by weight.

Abstract: In a known process for producing a quartz glass cylinder, a porous soot tube, which is sintered to form the quartz glass cylinder, is produced by depositing SiO2 particles on an outer cylindrical surface of a support, which rotates about the longitudinal axis thereof and has a layer of silicon carbide (SiC layer). In order on this basis to specify a support having a high resistance to fracture, which firstly can easily be removed and which secondly presents a low risk of contamination for the soot body, the invention proposes that the SiC layer is treated at a high temperature in an oxygen-containing atmosphere before the SiO2 particles are deposited, in such a manner that an SiO2 protective layer having a thickness of at least 0.1 ?m is produced by oxidation.

Abstract: In a known process for producing a quartz glass cylinder, a porous soot tube, which is sintered to form the quartz glass cylinder, is produced by depositing SiO2 particles on an outer cylindrical surface of a support, which rotates about the longitudinal axis thereof and has a layer of silicon carbide (SiC layer). In order on this basis to specify a support having a high resistance to fracture, which firstly can easily be removed and which secondly presents a low risk of contamination for the soot body, the invention proposes that the SiC layer is treated at a high temperature in an oxygen-containing atmosphere before the SiO2 particles are deposited, in such a manner that an SiO2 protective layer having a thickness of at least 0.1 ?m is produced by oxidation.

Abstract: A known method for producing synthetic quartz glass comprises the method steps: (a) forming a cylindrical SiO2 soot body having an inner portion and at least one free cylinder jacket surface surrounding the inner portion; (b) thermally drying the porous soot body; and (c) vitrifying the dried soot body with formation of the cylinder from synthetic quartz glass.

Abstract: In a known method for producing a dimensionally stable semi-finished product for use in producing fibers from synthetic quartz glass, an SiO2 soot layer is applied to the outer wall of a quartz glass inner cylinder and is subjected to a sintering treatment, wherein a sintering zone moves through the SiO2 soot layer from the outside to the inside. In order to achieve dimensionally accurate and low-deformation production as well as high cost efficiency based on said known method, it is proposed that the sintering treatment be interrupted before the sintering zone reaches the outer wall of the inner cylinder so that an intermediate layer made of synthetic quartz glass containing pores remains at the inner cylinder outer wall. The semi-finished product obtained in such a way is elongated into the optical component, wherein the intermediate layer sinters completely into transparent quartz glass.

Abstract: In a known method for producing quartz glass that is doped with nitrogen, an SiO2 base product is prepared in the form of SiO2 grains or in the form of a porous semi-finished product produced from the SiO2 grains and the SiO2 base product is processed into the quartz glass with the nitrogen chemically bound therein in a hot process in an atmosphere containing a reaction gas containing nitrogen. From this starting point, a method is provided for achieving nitrogen doping in quartz glass with as high a fraction of chemically bound nitrogen as possible. This object is achieved according to the invention in that a nitrogen oxide is used as the nitrogen-containing reaction gas, and that a SiO2 base product is used that in the hot process has a concentration of oxygen deficient defects of at least 2×1015 cm?3, wherein the SiO2 base product comprises SiO2 particles having an average particle size in the range of 200 nm to 300 ?m (D50 value).

Abstract: In a known method for coating a crucible for use at a high working temperature in a crucible drawing method for quartz glass, a base body wall of tungsten has applied thereto a protective layer containing a coating metal consisting of the group selected from iridium, rhenium, osmium and ruthenium. Starting therefrom, to provide a method for producing such a component exhibiting high corrosion resistance to the quartz glass melt at low material costs, it is suggested according to the invention that the protective layer should be produced from a layer material which contains tungsten and the coating metal, and in which the amount of the coating metal should be dimensioned such that it exceeds the limit amount of a coating metal-rich phase boundary of a solid mixture phase of tungsten and the coating metal, with the solid mixture phase being thermodynamically stable at the working temperature, by not more than 25 at. % (based on the total amount of tungsten and the coating metal in the layer material).

Abstract: A known method for producing synthetic quartz glass comprises the method steps: (a) forming a cylindrical SiO2 soot body having an inner portion and at least one free cylinder jacket surface surrounding the inner portion; (b) thermally drying the porous soot body; and (c) vitrifying the dried soot body with formation of the cylinder from synthetic quartz glass.

Abstract: An ideal quartz glass for a wafer jig for use in an environment having an etching effect is distinguished by both high purity and high resistance to dry etching. To indicate a quartz glass that substantially fulfills these requirements, it is suggested according to the invention that the quartz glass is doped with nitrogen at least in a near-surface area, has a mean content of metastable hydroxyl groups of less than 30 wt ppm and that its fictive temperature is below 1250° C. and its viscosity is at least 1013 dPa·s at a temperature of 1200° C. An economic method for producing such a quartz glass comprises the following method steps: melting an SiO2 raw material to obtain a quartz glass blank, the SiO2 raw material or the quartz glass blank being subjected to a dehydration measure, heating the SiO2 raw material or the quartz glass blank to a nitriding temperature in the range between 1050° C. and 1850° C.

Abstract: In a known method for drawing a tubular quartz glass strand, a crucible is fed with SiO2-containing start material, the start material is softened in the crucible and, as a softened quartz glass mass, is drawn vertically downwards as a tubular quartz glass strand along a drawing axis through an annular gap between an outer member and an inner member, which is arranged in a through hole of the outer member, of a drawing nozzle provided in the bottom area of the crucible.

Abstract: The invention relates to methods for producing a coated component consisting of quartz glass, according to which the component surface is at least partially provided with a SiO2 glass composition that differs from the quartz glass of the base body. The aim of the invention is to provide a novel way of coating a quartz glass component with a SiO2 glass composition that can be produced in a cost-effective, reproducible manner, with any thickness, and can fulfil various functions according to the concrete embodiment thereof. To this end, an amorphous slip containing SiO2 particles is produced and applied to the surface of the base body, forming a slip layer which is dried and then vitrified, forming a SiO2 glass composition. The quartz glass components coated in this way can be advantageously used especially in the production of semiconductors.

Abstract: An ideal quartz glass for a wafer jig for use in an environment having an etching effect is distinguished by both high purity and high resistance to dry etching. To indicate a quartz glass that substantially fulfills these requirements, it is suggested according to the invention that the quartz glass is doped with nitrogen at least in a near-surface area, has a mean content of metastable hydroxyl groups of less than 30 wt ppm and that its fictive temperature is below 1250° C. and its viscosity is at least 1013 dPa·s at a temperature of 1200° C. An economic method for producing such a quartz glass comprises the following method steps: melting an SiO2 raw material to obtain a quartz glass blank, the SiO2 raw material or the quartz glass blank being subjected to a dehydration measure, heating the SiO2 raw material or the quartz glass blank to a nitriding temperature in the range between 1050° C. and 1850° C.

Abstract: In a known method for coating a crucible for use at a high working temperature in a crucible drawing method for quartz glass, a base body wall of tungsten has applied thereto a protective layer containing a coating metal consisting of the group selected from iridium, rhenium, osmium and ruthenium. Starting therefrom, to provide a method for producing such a component exhibiting high corrosion resistance to the quartz glass melt at low material costs, it is suggested according to the invention that the protective layer should be produced from a layer material which contains tungsten and the coating metal, and in which the amount of the coating metal should be dimensioned such that it exceeds the limit amount of a coating metal-rich phase boundary of a solid mixture phase of tungsten and the coating metal, with the solid mixture phase being thermodynamically stable at the working temperature, by not more than 25 at. % (based on the total amount of tungsten and the coating metal in the layer material).

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. The quartz glass blank according to the invention is characterized by the following properties: a glass structure essentially free of oxygen defect sites, an H2-content in the range of 0.1×1016 molecules/cm3 to 4.0×1016 molecules/cm3, an OH-content in the range of 125 wt-ppm to 450 wt-ppm, an SiH group-content of less than 5×1016 molecules/cm3, a refractive index inhomogeneity, ?n, of less than 2 ppm, and a stress birefringence of less than 2 nm/cm.

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. The quartz glass blank according to the invention is characterized by the following properties: a glass structure essentially free of oxygen defect sites, an H2-content in the range of 0.1×1016 molecules/cm3 to 4.0×1016 molecules/cm3, an OH-content in the range of 125 wt-ppm to 450 wt-ppm, an SiH group-content of less than 5×1016 molecules/cm3, a refractive index inhomogeneity, ?n, of less than 2 ppm, and a stress birefringence of less than 2 nm/cm.

Abstract: The invention relates to a previously known method for producing synthetic silica glass, comprising the following steps: a gas stream containing a vaporizable initial substance, which can be converted into SiO2 by means of oxidation or flame hydrolysis, is formed; the gas stream is delivered to a reaction zone in which the initial substance is converted so as to form amorphous SiO2 particles; the amorphous SiO2 particles are deposited on a support so as to form an SiO2 layer; and the SiO2 is vitrified during or following deposition of the SiO2 particles in order to obtain the silica glass. The aim of the invention is to create an economical method for producing synthetic silica glass, which is characterized by a favorable damaging behavior towards short-wave UV radiation while being particularly suitable for producing an optical component used for transmitting high-energy ultraviolet radiation having a wavelength of 250 nm or less.

Abstract: An object of the present invention is to provide an improved blank such that an optical member of a high homogeneity can be obtained therefrom, and to provide a vessel and a heat treatment method for heat-treating a highly uniform synthetic quartz blank. In a first aspect of the invention a special designed blank is provided showing a concave shaped outer surface. In a second aspect of the invention a special designed vessel for heat-treating blanks is provided, whereby the degree of heat emission at the center is set higher than that of the surroundings.

Abstract: An object of the present invention is to provide an improved blank such that an optical member of a high homogeneity can be obtained therefrom, and to provide a vessel and a heat treatment method for heat-treating a highly uniform synthetic quartz blank. In a first aspect of the invention a special designed blank is provided showing a concave shaped outer surface. In a second aspect of the invention a special designed vessel for heat-treating blanks is provided, whereby the degree of heat emission at the center is set higher than that of the surroundings.

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.