Abstract: A method for producing a high purity synthetic quartz powder, characterized by using a tetramethoxysilane having a trimethoxymethylsilane content of at most 0.3 wt %, and converting it to a synthetic quartz by a sol-gel method.

Abstract: A method for producing an improved quartz glass crucible for pulling up silicon single crystals comprises forming a premolding by feeding powdered silicon dioxide into the mold and by then forming it into a layer along the inner surface of the mold; forming a crucible base body of a translucent quartz layer by heating the premolding from the inner side, thereby partially melting the powdered silicon dioxide, followed by cooling and solidifying the melt; forming a crystallization-promoter containing layer along the internal wall surface of the crucible body by scattering the crystallization promoter on the surface of the internal wall of the crucible body during or after forming the crucible base body; and forming a synthetic quartz glass inner layer by scattering and fusing a powder of silicon dioxide on the crystallization promoter-containing layer that is formed along the internal wall surface of the crucible base body.

Abstract: An anti-reflective reticle and a method by which the anti-reflective reticle is formed. Formed upon a first surface of a transparent substrate is a patterned metal layer. Formed upon the first surface of the transparent substrate including the patterned metal layer is a two-layer dielectric stack. The two layer dielectric stack has a first dielectric layer which is closer to the transparent substrate and a second dielectric layer which is formed directly upon the first dielectric layer. The first dielectric layer has an index of refraction greater than the index of refraction of the transparent substrate or the second dielectric layer. The second dielectric layer has a thickness of about one-quarter the wavelength of reflected light desired to be attenuated or eliminated from the surface of the reticle.

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: 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: The present invention provides a method for manufacturing an optical component that have increased transmittance in the ultraviolet region of the spectrum. The method includes the steps of cutting out a part from a block material; polishing optical sides of the part; subjecting the part to heat treatment at a temperature of between 100 and 900.degree. C.; and subjecting the part to acid treatment.

Abstract: A crucible in which a semiconductor material is melted and held during a crystal growing process. The crucible includes a body of vitreous silica having a bottom wall and a sidewall formation extending up from the bottom wall and defining a cavity for holding the molten semiconductor material. The sidewall formation has an inner and an outer surface. A first devitrification promoter on the inner surface of the sidewall formation is distributed such that a first layer of substantially devitrified silica is formed on the inner surface of the crucible which is in contact with the molten semiconductor material when the semiconductor material is melted in the crucible during the crystal growing process. A second devitrification promoter on the outer surface of the sidewall formation is distributed such that a second layer of substantially devitrified silica is formed on the outer surface of the crucible when the semiconductor material is melted in the crucible during the crystal growing process.

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: A method to produce fused quartz particulates from quartz sand is disclosed employing continuous withdrawal of the molten material from a furnace apparatus. The molten material is rapidly cooled as withdrawn causing thermal fracture which is followed by mechanically pulverizing the fragments to a desired particle size.

Abstract: A silicon melting crucible having a double structure, in which a quartz crucible is inserted inside of a carbon crucible, is provided with devices for preventing deformation, such as turning-down, buckling and bending at an upper portion of the quartz crucible, or invasion of an SiO gas into a space between the quartz crucible and the carbon crucible during pulling up of a silicon single crystal. According to one form of the invention an upper portion of the quartz crucible has a frusto-conical inclined portion with an angle of inclination desirably of from 5.degree. to 40.degree.. According to another form of the invention a carbon ring having a cross section of either L-shape or U-shape is applied to the upper portion of the quartz crucible and the carbon crucible.

Abstract: Quartz powder is fed into a rotating mold to form a crucible-like quartz powder layer body with the help of centrifugal force in the mold. The layer is melted by heating through the inner surface with an arc discharge to manufacture an outer crucible member. A hollow cylindrical inner crucible member having a beveled lower edge is welded to the outer crucible member while a temperature of the inner surface portion of the outer crucible member remains at 1400.degree. C. or higher by a remaining heat.

Abstract: A method for producing at least one capillary in a moldable material. The capillary has a large length in relation to its cross-section. A closed cavity is created within the moldable material and the material is stretched in at least one direction so that the cavity forms a substantially elliptical or parabolic capillary whose length is large in relationship to its cross-section. The material may be heated before stretching so that the cavity is expanded and shaped into an essentially spherical form. Suitable materials for the practice of the invention include glass, plastic, quartz, silicon, or metal.

Abstract: A method for forming a substantially flat planar lightwave optical circuit which has a substantially flat planar silica substrate and a sintered glassy lightguiding layer over the silica substrate. The structure is given a post treatment at an elevated temperature for a time sufficient to flatten said structure and overcome any distortion caused by the difference in the coefficient of thermal expansion of the substrate and any glassy layers formed over the substrate. Alternatively, the silica substrate may be heated and presagged to a predetermined degree to compensate for distortion or warpage which will occur in later processing.

Abstract: A method for fabricating a large-sized primary treated quartz glass tube by perforating a cylindrical quartz glass mother material by a hot carbon drill press-in-process followed by etching and washing. The large-sized primary treated quartz glass tube is converted to a large-sized quartz glass preform by combining it with a core glass rod for an optical fiber. Another embodiment is a method for fabricating a large-sized quartz glass tube by heating, hot drawing or hot drawing under pressure using a tool-free drawing method under control of an inside pressure of the large-sized primary treated quartz glass tube at a temperature ranging from 1600.degree. C. to 3000.degree. C. to satisfy a specific equation.

Abstract: An anti-reflective reticle and a method by which the anti-reflective reticle is formed. Formed upon a first surface of a transparent substrate is a patterned metal layer. Formed upon at least one of: (1) the first surface of the transparent substrate including the patterned metal layer; or (2) the surface of the transparent substrate opposite the patterned metal layer is a two-layer dielectric stack. The two layer dielectric stack has a first dielectric layer which is closer to the transparent substrate and a second dielectric layer which is formed directly upon the first dielectric layer. The first dielectric layer has an index of refraction greater than the index of refraction of the transparent substrate or the second dielectric layer. The second dielectric layer has a thickness of about one-quarter the wavelength of reflected light desired to be attenuated or eliminated from the surface of the reticle.

Abstract: In a quartz glass crucible obtained by heating and fusing a rotating layer (3) charged with a powder of silicon dioxide, impurity elements are controlled so that copper, chromium, and nickel each amount to 0.5 ppb or less, iron amounts to 120 ppb or less, and sodium amounts to 20 ppb or less. The silicon dioxide powder is supplied to a rotatable mold (1) having an open top, thereby forming a layer (3) charged with silicon dioxide along the inner peripheral wall of the mold. The layer (3) is internally heated and fused while covering the open top with a lid (5) having two or more holes (6,7), and the mold (1) is ventilated to discharge the high temperature gases through the holes (6,7).

Abstract: An apparatus for heating an elongated glass body, which, for example, may be used as a pre-form for the drawing of glass fibers, includes a rotatable first chuck wherein the first end of the elongated glass body may be rotatably secured. In addition the apparatus includes a second rotatable chuck whereat the second end of the elongated glass body is introduced into a quartz tube and this quartz tube is clamped into the rotatable second chuck. A burner, which is adapted to slide parallel to the longitudinal axis of the elongated glass tube, heats the elongated glass body in such a manner, that a so called fire polish of the elongated glass body for the improvement of its surface quality occurs. A method for heating the elongated glass body is also disclosed.

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: The present invention provides large, high-purity quartz glass plate with a high degree of smoothness and flatness, its manufacturing method and equipment. The invention is characterized by the procedure in which a quartz glass tube with an opening over a specific width, in the direction of the tube shaft, that is preferably band-shaped, is heated and softened in a band-shaped area over the entire width, in the direction of the tube shaft, progressing sequentially along the direction of tube circumference from a specific position on the glass tube. While softening and heating, the quartz glass tube is pulled in a line approximately tangential to the specific position to flatten the glass tube.

Abstract: A quartz glass component having a projection on a flat face is manufactured by molding a quartz glass body at a high temperature and under high pressure. The heating temperature is set to a range of from 1800.degree. to 2000.degree. C. and slight pressure is applied by the female die which forms the projection, or pressure in a direction against gravity. The molding die includes a graphite frame surrounding a molding space formed by a female die and a receiving die sandwiching the quartz glass body in the graphite frame. The space between the receiving die and the female die is width-reducible, the compositions of the graphite frame and the two graphite dies are made to differ, the female die and receiving die contacting the quartz glass body during pressure molding have a plurality of gas-permeable micropores such as in sintered graphite for example and are formed by a high-purity graphite material having air permeability.

Abstract: The high-purity, opaque quartz glass containing 3.times.10.sup.6 -9.times.10.sup.6 of closed cells having an average size of 20-40 .mu.m per 1 cm.sup.3, a ratio of closed cells having sizes of 100 .mu.m or more to the whole of cells being 1% or less, thereby showing 5% or less of linear transmittance for near infrared rays (.lambda.=900 nm) at a thickness of 1 mm is produced by compacting amorphous silica powder having an average particle size of 0.5-10 .mu.m, in which each of impurities selected from Li, Na, K, Fe, Ti and Al is 1 ppm or less, if any, and sintering the resultant green body at 1730.degree.-1850.degree. C.

Abstract: A process for the production of homogeneous ream-free bodies made of quartz glass or made of a glass having a high content of silicic acid, in which an essentially bar-shaped initial body is twisted about its longitudinal axis in a shaping step to form a twisted body radially homogenized in layers having axial layering. To make it possible to produce homogeneous large-volume bodies, in at least one further shaping step the twisted body is then softened in a heatable mold under a force acting in the axial direction to deform it in a direction transverse to its axial direction into the mold and form a glass bar, the longitudinal axis of which extends essentially perpendicular to the layering. The glass bar is then twisted about its longitudinal axis.

Abstract: A synthetic quartz glass optical member for an ultraviolet laser, suitably applicable as a stepper lens of a lithographer using an excimer laser beam and other optical members, wherein the quartz glass has a hydroxyl content of 10 to 100 ppm, a chlorine content of 200 ppm or less, a hydrogen content of 1.times.10.sup.16 molecules/cm.sup.3 or less, a homogeneity of refractive index of 5.times.10.sup.-6 or less in terms of .DELTA.n, and a birefringence of 5 nm/cm or less. The optical member can be produced by subjecting a volatile silicon compound to flame hydrolysis with oxyhydrogen flame, depositing the formed particulate silica on a heat-resistant support to prepare a porous silica matrix, heating the matrix in a vacuum as high as 1.times.10.sup.-2 Torr or above to a temperature of 1,400 .degree. C.

Abstract: Quartz glass obtained by flame-hydrolyzing a glass-forming raw material to obtain fine particles of quartz glass, having the fine particles of quartz glass deposited and grown on a substrate to obtain a porous quartz glass product and heating the porous quartz glass product to obtain a transparent quartz glass product, which has an OH content of not more than 10 ppm and a halogen content of at least 400 ppm and which contains hydrogen.

Abstract: A quartz tank member produced by a new method of production having continuous inner corner surfaces formed through bending and welding processes with welded seams being smooth without any hills, valleys, pits, crevasses, or irregularities therein.

Abstract: The disclosed process involves the feeding of particulate SiO.sub.2 into a rotating cylindrical furnace in which a gas plasma arc has been established, for melting the feed at a temperature of at least 2400.degree. C. The feed rate is regulated so that the rate of growth of the radius of the ingot melt will not exceed the rate at which bubbles move through the melt to the inner cylindrical surface. The preferred apparatus is a rotating horizontal furnace having a pair of opposing hollow electrodes mounted in its opposing end surfaces for establishment of an arc therebetween. A feeding device introduces the SiO.sub.2 feed through the open bore of one of the electrodes for melting by the plasma arc.

Abstract: A body of cerium-doped quartz glass is manufactured by melting together silicon oxide and a cerium (III) silicate compound, preferably Ce.sub.2 Si.sub.2 O.sub.7, in a reducing atmosphere. The invention provides a method of manufacturing said cerium-silicate compound having a tetragonal crystal structure. The quartz glass manufactured can be suitably used in a lamp envelope of UV-absorbing quartz glass, the water content in the quartz glass being less than 1 ppm.

Abstract: A process for the production of a glass by the vacuum melting method using silica as a raw material is disclosed, comprising filing a silica fine powder in a suitable vessel, heating it in the presence of an accelerator for phase conversion to obtain a porous formed body consisting of a cristobalite phase, and then heating and melting the formed body in vacuo. According to the present invention, a transparent and active glass having a high quality can be produced at an inexpensive cost.

Abstract: The present invention relates to a process for the production of a glass from silica as a raw material by a vacuum melting method, in which a high quality glass is produced efficiently by compounding a silica powder containing an excess amount of the accelerator for phase conversion and silica powders containing substantially no such accelerator or by introducing silica powders in a solution containing an accelerator for phase conversion, adding an acid or basic component to the mixture to adjust the pH thereof, stirring the mixture for mixing, and subjecting the mixture to dehydration and drying to obtain silica powders containing the accelerator for phase conversion in proper quantities, filling the resultant silica powders in a vessel and heating the powder to form a sintered molded body having cristobalite phase having a self-supporting property and also having a proper matrix strength and a high porosity, and then heating the sintered body under vacuum.

Abstract: A process for production of a glass by a vacuum melting method using silica as raw materials comprising heating silica powders in the presence of an accelerator for phase conversion to convert them into a sintered body having cristobalite phase; molding or repowdering the sintered body; containing or filling the resulted sintered body in a container having a desired shape; and then heating and melting it in vacuo for glass formation, or accumulating a plurality of the sintered bodies into a desired shape; and then heating and melting it for glass formation, whereby a high-quality glass ingot having a desired shape or a larger glass ingot can be readily obtained without reduction in productivity.

Abstract: The present invention relates to a process for production of a glass by the vacuum melting method using silica as raw material and comprises uniformly preheating a silica powder containing an accelerator for phase conversion to about 800.degree. C.; filling the preheated silica powder in a container while substantially maintaining the temperature; further heating the silica powder to convert it into a sintered body having a cristobalite phase; and then heating and melting the sintered body in vacuum for glass formation, whereby not only are improvments in raw material efficiency and productivity by shortening of the heating time achieved, but also the formation of cracks on the surface of the resulted sintered body which has been one of the important reasons for resulting in products of sub-standard can be substantially completely avoided.

Abstract: A method of manufacturing practically stria-free, bubble-free, and homogeneous quartz-glass plates of any desired configuration and with a surface area that exceeds the cross-section of the full circular quartz-glass cylinder that is employed as a starting material. The cylinder is continuously lowered into a furnace shell flooded with an inert gas, in which it is heated to a flowing temperature in the range of 1700.degree. to 1900.degree. C. until some of the quartz-glass flows off into a graphite crucible. The crucible is preferably clad with zirconium-oxide.

Abstract: A method is described according to which articles of quartz glass, particrly quartz crucibles for use in crucible pulling according to Czochralski of high-purity synthetic quartz glass can be produced. High-purity silicon tetrachloride is hydrolized with water. The hydrolysis product is separated, dried, shaped, sintered and superficially fused.

Abstract: Tubular body of fused quartz and quartz glass with a seamless transition from the fused-quartz zone to the quartz-glass zone. The body is manufactured continuously in a hollow rotating metal cylinder by disposing silica against the rotating mold and adding thereto, such as in an annular zone therein, rock crystal or synthetic silicon dioxide and fusing the rock crystal or synthetic silicon dioxide to the fused silica whereby no seam is formed.

Abstract: Reaction vessels, furnace tubes, heating and cooling enclosures frequently have parts such as access ports, inlet tubes, inspection windows, etc. made of thermally transparent materials such as plastic, glass, quartz, oxides, nitrides and sulfides. When these parts extend outside the hot zone, they can act as "light pipes" carrying appreciable amounts of thermal radiation which can damage thermally sensitive gaskets or other materials used to secure external couplings or end closure flanges to these parts. Thermal radiation induced gasket damage is a frequent cause of stuck flanges and couplings. This problem is avoided by inserting a thermal radiation scattering region in the thermally transparent material between the hot zone and the end closure or gaskets. The thermal radiation is scattered and dispersed, so that the end zones receive less radiation and remain cooler. Milky quartz is a suitable scattering material for use with quartz furnace tubes or bell jars.

Abstract: The elongated burner is described which is capable of providing a ribbon of flame through which particulate material as small as 1 micron is uniformly dispersed and transported onto a rotating forming surface for formation of an ingot. In a preferred embodiment the burner is provided with a hollow interior defined by a cylindrical surface interrupted by a longitudinal groove in communication with a longitudinal discharge slot. The sides of the groove are sloped at an angle steeper than the angle of repose of the particulate material. In the preferred embodiment the exterior surface of the burner is likewise provided with a longitudinal groove in communication with the discharge slot and providing two surfaces angled toward each other and toward the path through which the discharged material travels.

Abstract: An open tubular or capillary chromatographic column made from drawn silica tubing having an exterior coating for protection from abrasion and moisture and means for holding it in a desired configuration.

Abstract: Method of preparing granular quartz glass which comprises heating a porous granulated silica gel having an alkoxy group content equal to or less than 1 weight percent and a total impurity content of less than 1 part per million, the porous granulated silica gel obtained by hydrolysis of an orthosilicic acid ester of an aliphatic alcohol at a temperature up to 1400.degree. C.

Abstract: The apparatus for manufacturing an ingot includes a rotatable housing with an inner surface defining an opening therethrough along the rotational axis of the housing. The housing is rotated about the rotational axis. The housing includes a layer of insulating material located between the inner and outer surfaces of the housing. Particulate material is deposited along the inner surface while the housing is rotating and the particulate material is heated above its melting temperature while the housing is rotating, the rotational movement holding the molten particulate material in place by centrifugal force on the inner surface for forming an ingot.

Abstract: Method of preparing granular quartz glass which comprises heating a porous granulated silica gel having an alkoxy group content equal to or less than 1 weight percent and a total impurity content of less than 1 part per million, the porous granulated silica gel obtained by hydrolysis of an orthosilicic acid ester of an aliphatic alcohol at a temperature up to 1400.degree. C.

Abstract: A process is disclosed for making vitreous silica crucibles of exceptional high quality for use in the growing of a silicon crystal from molten silicon. The crucibles are formed from fine particles of high purity fused silica by slip casting or other suitable process, are dried and fired to provide a rigid porous body, and are thereafter sintered to a high density, preferably to the transparent state. The invention solves the problem of spalling, blistering and cracking during crystal growing and the resulting contamination of the molten silicon, which has long plagued the industry, by eliminating water from the fused silica particles before the porous body is sintered to the transparent state. Said body is thoroughly dried in a vacuum furnace at a high temperature and at a sub-atmospheric pressure low enough to remove the chemically bound water which cannot be removed by heat alone.

Abstract: Multi-layer radiator of plastic material consisting of planar elements comprising an array of vertical water pipes horizontal collecting channels, wherein the planar elements are first connected by straps fastened in the readily accessible border zones of the elements to form units which are then welded together at their end-faces. The radiator can be produced with a few operating steps and the manufacturing costs are considerably reduced.

Abstract: The apparatus is a rotatable resistance heating furnace including a rotatable cylindrical body portion having an interior space in the form of a truncated cone. The base of the truncated cone forms a discharge opening for rapid discharge of the amorphous silica. The furnace is provided with a resistance heating element which extends into the furnace interior through a top opening. In one embodiment a slidable filling tube is provided for charging the furnace during rotation thereof. The process utilizes the above-described apparatus and involves heating the crystalline silica to a temperature sufficient to convert it to the amorphous state, evacuating the furnace during the conversion to draw off by-product gases, and rotating the furnace to a speed sufficient to bring about a separation between the silica charge and the resistance heating element.

Abstract: Dislocation and etch channel-free quartz resonator blanks are made from a cultured quartz stone by visualizing the dislocation-free areas of the cultured quartz stone by X-ray topography, cutting seed plates for the next generation of crystal growth from the dislocation-free areas of the cultured quartz stone, growing dislocation free quartz from said seed plates using conventional growth techniques, and cutting dislocation-free quartz resonator blanks from said dislocation-free quartz.