Abstract: A silicon carbide powder according to the embodiment includes nitrogen having a concentration in a range of about 100 ppm to about 5000 ppm. A method for manufacturing silicon carbide powder according to the embodiment includes preparing a mixture by mixing a silicon source including silicon with a solid carbon source or a carbon source including an organic carbon compound; heating the mixture; cooling the mixture; and supplying a nitrogen-based gas into the mixture.

Abstract: Porous three-dimensional networks of polyimide and porous three-dimensional networks of carbon and methods of their manufacture are described. For example, polyimide aerogels are prepared by mixing a dianhydride and a diisocyanate in a solvent comprising a pyrrolidone and acetonitrile at room temperature to form a sol-gel material and supercritically drying the sol-gel material to form the polyimide aerogel. Porous three-dimensional polyimide networks, such as polyimide aerogels, may also exhibit a fibrous morphology. Having a porous three-dimensional polyimide network undergo an additional step of pyrolysis may result in the three dimensional network being converted to a purely carbon skeleton, yielding a porous three-dimensional carbon network. The carbon network, having been derived from a fibrous polyimide network, may also exhibit a fibrous morphology.

Abstract: A process and apparatus for preparing a nanopowder are presented. The process comprises feeding a reactant material into a plasma reactor in which is generated a plasma flow having a temperature sufficiently high to vaporize the material; transporting the vapor with the plasma flow into a quenching zone; injecting a preheated quench gas into the plasma flow in the quenching zone to form a renewable gaseous condensation front; and forming a nanopowder at the interface between the renewable controlled temperature gaseous condensation front and the plasma flow.

Abstract: An SiC single crystal includes a low dislocation density region (A) where the density of dislocations each of which has a Burgers vector in a {0001} in-plane direction (mainly a direction parallel to a <11-20> direction) is not more than 3,700 cm/cm3. Such an SiC single crystal is obtained by: cutting out a c-plane growth seed crystal of a high offset angle from an a-plane grown crystal; applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range; cutting out a c-plane growth crystal of a low offset angle from the obtained c-plane grown crystal; and applying c-plane growth so that the density of screw dislocations introduced into a c-plane facet may fall in a prescribed range. An SiC wafer and a semiconductor device are obtained from such an SiC single crystal.

Abstract: This disclosure concerns a method of making silicon carbide involving adding agricultural husk material to a container, creating a vacuum or an inert atmosphere inside the container, applying conventional heating or microwave heating, heating rapidly, and reacting the material and forming silicon carbide (SiC).

Abstract: A method of growing an epitaxial layer on a substrate is generally provided. According to the method, the substrate is heated in a chemical vapor deposition chamber to a growth temperature in the presence of a carbon source gas, then the epitaxial layer is grown on the substrate at the growth temperature, and finally the substrate is cooled in a chemical vapor deposition chamber to at least about 80% of the growth temperature in the presence of a carbon source gas. Substrates formed from this method can have a carrier lifetime between about 0.25 ?s and about 9.9 ?s.

Abstract: A particle formed of silica and carbon having a low impurity content and an excellent reactivity is provided. Also provided is a method of producing a silica and carbon-containing material including: (B) a carbon mixing step of mixing an aqueous alkali silicate solution having a silicon concentration within the liquid portion of at least 10 wt % with carbon so as to obtain a carbon-containing aqueous alkali silicate solution; and (C) a silica recovery step of mixing the carbon-containing aqueous alkali silicate solution with a mineral acid so as to cause carbon and silicon within the liquid portion to precipitate as particles formed of silica and carbon and thus obtaining a particle-containing liquid substance, then solid-liquid separating the liquid substance so as to obtain a solid portion of a silica and carbon-containing material which is an assembly of particles formed of silica and carbon and a liquid portion containing impurities.

Abstract: Systems and methods for heating a non-combustion chemical reactor with thermal energy from a geothermal heat source are described. A working fluid is directed from the geothermal heat source to the chemical reactor to transfer heat. The working fluid can be circulated in a closed system so that it does not contact material at the geothermal heat source, or in an open system that allows the working fluid to intermix with material at the geothermal heat source. When intermixing with material at the geothermal heat source, the working fluid can transport donor substances at the geothermal heat source to the chemical reactor.

Abstract: A method of forming an SiC crystal including placing in an insulated graphite container a seed crystal of SiC, and supporting the seed crystal on a shelf, wherein cushion rings contact the seed crystal on a periphery of top and bottom surfaces of the seed crystal, and where the graphite container does not contact a side surface of the seed crystal; placing a source of Si and C atoms in the insulated graphite container, where the source of Si and C atoms is for transport to the seed crystal to grow the SiC crystal; placing the graphite container in a furnace; heating the furnace; evacuating the furnace; filling the furnace with an inert gas; and maintaining the furnace to support crystal growth to thereby form the SiC crystal.

Abstract: Provided is a monocrystalline silicon carbide ingot containing a dopant element, wherein a maximum concentration of the dopant element is less than 5×1017 atoms/cm3 and the maximum concentration is 50 times or less than that of a minimum concentration of the dopant element. Also provided is a monocrystalline silicon carbide wafer made by cutting and polishing the monocrystalline silicon carbide ingot, wherein a electric resistivity at room temperature of the wafer is 5×103 ?cm or more. Further provided is a method for manufacturing the monocrystalline silicon carbide including growing the monocrystalline silicon carbide on a seed crystal from a sublimation material by a sublimation method. The sublimation material includes a solid material containing a dopant element, and the specific surface of the solid material containing the dopant element is 0.5 m2/g or less.

Abstract: A method of fabricating silicon carbide according to the embodiment comprises the steps of preparing a mixture by mixing a silicon source comprising silicon with a solid carbon source or a carbon source comprising an organic carbon compound; supplying binder into the mixture to granulate the mixture; and reacting the granulated mixture.

Abstract: This invention relates to a method for the manufacture of monolithic ingot of silicon carbide comprising: i) introducing a mixture comprising polysilicon metal chips and carbon powder into a cylindrical reaction cell having a lid; ii) sealing the cylindrical reaction cell of i); iii) introducing the cylindrical reaction cell of ii) into a vacuum furnace; iv) evacuating the furnace of iii); v) filling the furnace of iv) with a gas mixture which is substantially inert gas to near atmospheric pressure; vi) heating the cylindrical reaction cell in the furnace of v) to a temperature of from 1600 to 2500° C.; vii) reducing the pressure in the cylindrical reaction cell of vi) to less than 50 torr but not less than 0.05 torr; and viii) allowing for substantial sublimation and condensation of the vapors on the inside of the lid of the cylindrical reaction cell of vii).

Abstract: A method of fabricating silicon carbide according to the embodiment comprises the steps of preparing a mixture by mixing a dry silicon source with a carbon source comprising an organic carbon compound; and reacting the mixture, wherein a viscosity of the carbon source is in a range of 20 cps to 1000 cps.

Abstract: A method is provided for recycling and treating the wastes of silicon wafer cutting and polishing processes. To begin with, a dewatered filter cake is mixed with water so that the filter cake is diluted to form a working fluid. The water reacts with silicon in the filter cake to produce silicon dioxide and hydrogen. After the hydrogen is extracted for storage, specific gravity separation takes place via water so that silicon carbide and silicon particles are separated for sorting. Then, solid-liquid separation is performed on the remaining working fluid to separate silicon dioxide (solid) from water and PEG (liquid), before PEG is separated from water. Thus, the useful silicon particles, silicon carbide, silicon dioxide, and PEG are recycled from the filter cake to reduce the total amount of wastes. Moreover, as the side product, hydrogen, is of high commercial value, the method also adds value to recycling.

Abstract: Provided is a carbon layer derived from carbide ceramics, wherein metal or non-metal atoms are extracted selectively from the surface of carbide ceramics to form voids, which, in turn, are filled with carbon synthesized by a carbon compound, thereby providing improved roughness and hardness, as well as to a method for preparing the same.

Abstract: A process for manufacturing SiC wherein the emissions of polluting gases are minimized, by reduction of silicon oxide by an excess of carbon, the process including electrically heating a resistor at the heart of a mixture of raw materials consisting of a carbon-based source chosen from petroleum cokes and a source of silicon, especially a silica having a purity of greater than 95% of SiO2, in order to give rise, at a temperature above 1500° C., to the simplified reaction: SiO2+3C=SiC+2CO (1), wherein the carbon-based source first undergoes a treatment for removing the contained hydrogen, so that its elemental hydrogen content (EHWC) is less than 2% by weight.

Abstract: A method of fabricating silicon carbide powder according to the embodiment comprises the steps of preparing a mixture by mixing a silicon source comprising silicon with a carbon source comprising a solid carbon source or an organic carbon compound; reacting the mixture; and controlling the reacting of the mixture, wherein the step of controlling the reacting comprises a step of supplying process gas or reaction product gas.

Abstract: A liquid mixture is prepared by using a liquid phenolic resin (PL-2818) serving as a carbon source. While an inert gas is introduced into the liquid mixture, a released gas is discharged. Then, the liquid mixture is dried in a reduced-pressure atmosphere, and thereby the nitrogen dissolved in the liquid mixture can be reduced. In this way, the amount of nitrogen content after burning can be reduced.

Abstract: A lightweight proppant with high crush strength can include a ceramic such as silicon carbide or silicon nitride.

Abstract: When an SiC single crystal having a large diameter of a {0001} plane is produced by repeating a-plane growth, the a-plane growth of the SiC single crystal is carried out so that a ratio Sfacet (=S1×100/S2) of an area (S1) of a Si-plane side facet region to a total area (S2) of the growth plane is maintained at 20% or less.

Abstract: The invention relates to a firing support for ceramics formed from a carbon substrate at least partially covered by a coating based on silicon carbide (SiC), said coating additionally adhering to said substrate. The invention also relates to a process for obtaining such a support.

Abstract: Provided is a monocrystalline silicon carbide ingot containing a dopant element, wherein a maximum concentration of the dopant element is less than 5×1017 atoms/cm3 and the maximum concentration is 50 times or less than that of a minimum concentration of the dopant element. Also provided is a monocrystalline silicon carbide wafer made by cutting and polishing the monocrystalline silicon carbide ingot, wherein a electric resistivity at room temperature of the wafer is 5×103 ?cm or more. Further provided is a method for manufacturing the monocrystalline silicon carbide including growing the monocrystalline silicon carbide on a seed crystal from a sublimation material by a sublimation method. The sublimation material includes a solid material containing a dopant element, and the specific surface of the solid material containing the dopant element is 0.5 m2/g or less.

Abstract: Disclosed is a method for hardening an interface of a carbon material by using nano silicon carbide coating. A carbon material-aluminum composite prepared by the disclosed method is light in weight, and has a high dynamic strength, and thus can be applied to currently used cars and aluminum wheels. Furthermore, the composite can be utilized as a material for aircrafts, spacecraft, ships, etc. requiring a high strength.

Abstract: Provided is an exclusive operation control apparatus which, when input operations of a plurality of users compete with each other, displays a content on which the plurality of input operations are reflected, instead of performing only one of the input operations. An operation determination section receives input information from the plurality of users, and determines an operation. An exclusive operation determination section determines an exclusive operation concerning a new operation by using the new operation and a previous operation. The content copying section copies the content based on a result of the determination. The content management section receives the new operation from the operation determination section and, when the new operation is an operation on the copied content, generates and displays on a display device display data which is obtained by reflecting the new operation on the copied content.

Abstract: A method for revitalizing worn and fatigued silicon carbide powder thermally reacted it continuously with a mixture of silicon oxide powder and/or carbon powder and a boron and carbon-containing additive in a non-oxidizing atmosphere at a temperature higher than 1850 degrees C. but lower than 2400 degrees C.

Abstract: An object of the present invention is to provide more inexpensive high purity crystalline silicon which can satisfy not only a quality required to a raw material of silicon for a solar cell but also a part of a quality required to silicon for an up-to-date semiconductor and a production process for the same and provide high purity silicon tetrachloride used for production of high purity crystalline silicon and a production process for the same. The high purity crystalline silicon of the present invention has a boron content of 0.015 ppmw or less and a zinc content of 50 to 1000 ppbw. The production process for high purity crystalline silicon according to the present invention is characterized by that a silicon tetrachloride gas and a zinc gas are supplied to a vertical reactor to react them at 800 to 1200° C.

Abstract: A single crystal silicon carbide substrate has a 4H-polytype crystal structure, has with nitrogen atoms doped as a conduction impurity with an atomic concentration of more than 1×1016/cm3, and has a main surface containing a circle having a diameter of 5 cm. The single crystal silicon carbide substrate includes only one of a facet region and a non-facet region. Thus, variation in nitrogen atom concentration in the single crystal silicon carbide substrate can be suppressed.

Abstract: A method of producing silicon carbide is provided. The method includes heating a cured product of a curable silicone composition in a non-oxidizing atmosphere at a temperature exceeding 1,500° C. but not more than 2,600° C. The method is capable of producing high-purity silicon carbide simply and at a high degree of productivity, and is capable of simply producing a silicon carbide molded item having a desired shape and dimensions.

Abstract: A method of forming micrometric or millimetric sized granules by the agglomeration of nanometric sized particles, comprising the addition of a set of nanometric sized particles into a container having an inside wall surface with a circular or approximately circular section and setting the set of particles in motion along said inside wall surface by rotating the container about a rotation axis passing through said container. The setting in motion of the particles is done in a dry state and the container is rotated continuously at constant speed for several consecutive hours.

Abstract: Provided are: a readily sinterable silicon carbide powder substantially having a stoichiometric composition and from which a dense sintered body can be obtained; a silicon carbide ceramic sintered body having a low specific resistance; and a production method thereof. This readily sinterable silicon carbide powder has a carbon/silicon elemental ratio of 0.96 to 1.04, an average particle diameter of 1.0 to 100 ?m, and a ratio of 20% or less of an integrated value of an absorption intensity in a chemical shift range of 0 to 30 ppm to an integrated value of an absorption intensity in a chemical shift range of 0 to 170 ppm, in a 13C-NMR spectrum. By sintering this silicon carbide powder under pressure, there can be produced a dense sintered body having a low specific resistance and a high purity.

Abstract: In a crystal growth apparatus and method, polycrystalline source material and a seed crystal are introduced into a growth ambient comprised of a growth crucible disposed inside of a furnace chamber. In the presence of a first sublimation growth pressure, a single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a first gas that includes a reactive component that reacts with and removes donor and/or acceptor background impurities from the growth ambient during said sublimation growth. Then, in the presence of a second sublimation growth pressure, the single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a second gas that includes dopant vapors, but which does not include the reactive component.

Abstract: The invention relates to a chemical reactor with a nanometric superstructure, comprising at least one member wherein at least one reaction chamber is arranged, and said reaction chamber being filled at least partially with a high specific surface area material having a specific surface area greater than 5 m2/g, and characterized in that said high specific surface area material is selected from nanotubes or nanofibers. These nanotubes or nanofibers are preferably selected in the group consisting of carbon nanofibers or nanotubes, ?-SiC nanofibers or nanotubes, TiO2 nanofibers or nanotubes. They may be deposited on an intermediate structure selected in the group consisting of glass fibers, carbon fibers, SiC foams, carbon foams, alveolar ?-SiC foams, said intermediate structure filling the reaction chamber of said reactor at least partially.

Abstract: An SiC crystal has Fe concentration not higher than 0.1 ppm and Al concentration not higher than 100 ppm. A method of manufacturing an SiC crystal includes the following steps. SiC powders for polishing are prepared as a first source material. A first SiC crystal is grown by sublimating the first source material through heating and precipitating an SiC crystal. A second source material is formed by crushing the first SiC crystal. A second SiC crystal is grown by sublimating the second source material through heating and precipitating an SiC crystal. Thus, an SiC crystal and a method of manufacturing an SiC crystal capable of achieving suppressed lowering in quality can be obtained.

Abstract: The invention relates to a process for aftertreating carbon black, wherein the carbon black is subjected to a carrier gas flow in a fluidized bed apparatus in the lower region of the apparatus, an additional gas stream is introduced into the fluidized bed apparatus, and the carbon black is aftertreated in the fluidized bed which arises.

Abstract: A method of growing an epitaxial layer on a substrate is generally provided. According to the method, the substrate is heated in a chemical vapor deposition chamber to a growth temperature in the presence of a carbon source gas, then the epitaxial layer is grown on the substrate at the growth temperature, and finally the substrate is cooled in a chemical vapor deposition chamber to at least about 80% of the growth temperature in the presence of a carbon source gas. Substrates formed from this method can have a carrier lifetime between about 0.25 ?s and about 9.9 ?s.

Abstract: Provided is an inexpensive seed material for liquid phase epitaxial growth of silicon carbide. A seed material 12 for liquid phase epitaxial growth of a monocrystalline silicon carbide includes a surface layer containing a polycrystalline silicon carbide with a 3C crystal polymorph. Upon X-ray diffraction of the surface layer thereof, a first-order diffraction peak corresponding to a (111) crystal plane is observed as a diffraction peak corresponding to the polycrystalline silicon carbide with a 3C crystal polymorph but no other first-order diffraction peak having a diffraction intensity of 10% or more of the diffraction intensity of the first-order diffraction peak corresponding to the (111) crystal plane is observed.

Abstract: Provided is a feed material for epitaxial growth of a monocrystalline silicon carbide capable of increasing the rate of epitaxial growth of silicon carbide. A feed material 11 for epitaxial growth of a monocrystalline silicon carbide includes a surface layer containing a polycrystalline silicon carbide with a 3C crystal polymorph. Upon X-ray diffraction of the surface layer, a diffraction peak corresponding to a (111) crystal plane and a diffraction peak other than the diffraction peak corresponding to the (111) crystal plane are observed as diffraction peaks corresponding to the polycrystalline silicon carbide with a 3C crystal polymorph.

Abstract: This disclosure concerns a method of making silicon carbide involving adding one from the group of rice husk material, sorghum, peanuts, maple leaves, and/or corn husk material to a container, creating a vacuum or an inert atmosphere inside the container, applying conventional heating or microwave heating, heating rapidly, and reacting the material and forming silicon carbide (SiC).

Abstract: Provided is an inexpensive seed material for liquid phase epitaxial growth of silicon carbide. A seed material 12 for liquid phase epitaxial growth of a monocrystalline silicon carbide includes a surface layer containing a polycrystalline silicon carbide with a 3C crystal polymorph. Upon Raman spectroscopic analysis of the surface layer with an excitation wavelength of 532 nm, a peak other than a TO peak and an LO peak is observed as a peak derived from the polycrystalline silicon carbide with a 3C crystal polymorph.

Abstract: A silicon carbide powder for the production of a silicon carbide single crystal has an average particle diameter of 100 ?m or more and 700 ?m or less and a specific surface area of 0.05 m2/g or more and 0.30 m2/g or less. A method for producing a silicon carbide powder for the production of the silicon carbide single crystal including sintering a silicon carbide powder having an average particle diameter of 20 ?m or less under pressure of 70 MPa or less at a temperature of 1900° C. or more and 2400° C. or less and in a non-oxidizing atmosphere, thereby obtaining a sintered body having a density of 1.29 g/cm3 or more; adjusting particle size by means of pulverization of the sintered body; and removing impurities by means of an acid treatment.

Abstract: A metal carbide ceramic fiber having improved mechanical properties and characteristics and improved processes and chemical routes for manufacturing metal carbide ceramic fiber. Metal carbide ceramic fibers may be formed via reaction bonding of a metal-based material (e.g. boron) with the inherent carbon of a carrier medium. One embodiment includes a method of making a metal carbide ceramic fiber using VSSP to produce high yield boron carbide fiber. Embodiments of the improved method allow high volume production of high density boron carbide fiber. The chemical routes may include a direct production of boron carbide fiber from boron carbide powder (B4C) and precursor (e.g. rayon fiber) having a carbon component to form a B4C/rayon fiber that may be processed at high temperature to form boron carbide fiber, and that may be subsequently undergo a hot isostatic pressing to improve fiber purity. Another route may include a carbothermal method comprising combining boron powder (B) with a precursor (e.g.

Abstract: Provided is a method of processing wafer waste. First, the wafer waste is separated into liquid mixture and solid mixture by solid-liquid separation. Next, a recovered cutting fluid is isolated from the liquid mixture by evaporation. The solid mixture is mixed with a first aqueous solvent to obtain a mixing slurry. Then, the mixing slurry is separated into a silicon-containing mixture and a silicon carbide-containing mixture. After suitable washing process, a recovered silicon and a recovered silicon carbide are finally obtained. Thus, the method recovers the cutting fluid, silicon and silicon carbide in the same process, which can reduce the environmental contaminations caused by wafer waste and reduce the manufacture cost of wafer production by recovering the wafer waste.

Abstract: Disclosed is a silicon carbide substrate which has less high frequency loss and excellent heat dissipating characteristics. The silicon carbide substrate (S) is provided with a first silicon carbide layer (1), which is composed of a polycrystalline silicon carbide, and a second silicon carbide layer (2), which is composed of polycrystalline silicon carbide formed on the surface of the first silicon carbide layer. The second silicon carbide layer (2) has a high-frequency loss smaller than that of the first silicon carbide layer (1), the first silicon carbide layer (1) has a thermal conductivity higher than that of the second silicon carbide layer (2), and on the surface side of the second silicon carbide layer (2), the high-frequency loss at a frequency of 20 GHz is 2 dB/mm or less, and the thermal conductivity is 200 W/mK or more.

Abstract: Silicon-containing products, such as silicon, silicon carbide and silicon nitride, containing less than 0.01 weight percent total mineral impurities and selectively determined carbon-to-silicon ratios. The products are derived from plant matter, such as rice hulls and rice straw, containing at least three weight percent silica. Methods are provided for making such high purity silicon-containing products by leaching silica-containing plant matter with aqueous sulfuric acid under controlled temperatures, pressures and reaction times to remove minerals and metals while adjusting the mole ratio of fixed carbon to silica, and then thermally treating under controlled conditions to produce the desired product.

Abstract: A silicon carbide substrate has a high-frequency loss equal to or less than 2.0 dB/mm at 20 GHz is effective to mount and operate electronic components. The silicon carbide substrate is heated at 2000° C. or more to be reduced to the high-frequency loss equal to 2.0 dB/mm or less at 20 GHz. Moreover, manufacturing the silicon carbide substrate by CVD without flowing nitrogen into a heater enables the high-frequency loss to be reduced to 2.0 dB/mm or less.

Abstract: Disclosed are a silicon carbide and a method for manufacturing the same. The method for manufacturing silicon carbide includes mixing a silicon source with a carbon source, and heating a mixture of the silicon and carbon sources to form the silicon carbide. At least one of the silicon source and the carbon source has an average grain size of about 10 nm to about 100 nm.

Abstract: Provided is a method for manufacturing silicon carbide. The method includes mixing a dry silicon source, a solid carbon source, and a binder with each other and heating the mixed source to form silicon carbide.

Abstract: A method for manufacturing a nanoscale cage of a material suitable for forming a molecular layer, including a step of shaping and packaging an object in the general shape of a revolving cylinder, the shaping and packaging step being adapted according to the position of the value of the diameter of the revolving cylinder relative to a threshold below which a folding of the ends of the cylinder is promoted.

Abstract: A spherical ? type crystal silicon carbide powder having an average particle diameter is of 5 ?m-60 ?m, specific pore volume of the inside pores in it having a diameter of 1 ?m or smaller is 0.02 cc/g or smaller, specific surface area of it is 1 m2/g or smaller, and average aspect ratio (short diameter/long diameter) of it is 0.65 or higher is proposed; a method for manufacturing the same including the steps of (1) spray-drying a slurry of a raw material silicon carbide powder which has an average particle diameter of 1 ?m or smaller and has an ? type crystal, to obtain porous and spherical particles, and (2) sintering the thus obtained porous and spherical particles, is also proposed.

Abstract: A method of producing silicon carbide is provided. The method includes heating a cured product of a curable silicone composition in a non-oxidizing atmosphere at a temperature exceeding 1,500° C. but not more than 2,600° C. The method is capable of producing high-purity silicon carbide simply and at a high degree of productivity, and is capable of simply producing a silicon carbide molded item having a desired shape and dimensions.