Abstract: Disclosed are processes and reactor apparatus for rapidly producing large diameter, high-purity polycrystalline silicon rods for semiconductor applications. A.C. current, having a fixed or variable high frequency in the range of about 2 kHz to 800 kHz, is provided to concentrate at least 70% of the current in an annular region that is the outer 15% of a growing rod due to the “skin effect.

Abstract: Silicon nanowires and silicon nanoparticle chains are formed by the activation of silicon monoxide in the vapor phase. The silicon monoxide source may be solid or gaseous, and the activation may be by thermal excitation, laser ablation, plasma or magnetron sputtering. The present invention produces large amounts of silicon nanowires without requiring the use of any catalysts that may cause contamination.

Abstract: A method and an apparatus have been developed to grow beta-silicon carbide nanorods, and prepare patterned field-emitters using different kinds of chemical vapor deposition methods. The apparatus includes graphite powder as the carbon source, and silicon powder as silicon sources. Metal powders (Fe, Cr and/or Ni) are used as catalyst. Hydrogen was the only feeding gas to the system.

Abstract: The invention features a method of continuous crystalline growth. A granular source material is introduced into a hopper. A volume of the granular source material exiting the hopper is disposed on a translationally moving belt. The volume of the granular source material forms an angle of repose with the moving belt. The granular source material disposed on the moving belt is continuously fed into a crucible comprising a melt of the granular source material at a rate based on the angle of repose, the speed of the belt, and the size of the opening of the hopper. A crystalline ribbon is continuously grown by solidifying the melt.

Abstract: A thermal plasma annealing system comprises a radiation irradiation means for irradiating a thin film formed on a substrate with heat or radiation emitted from a thermal plasma. This annealing system enables a material relatively sensitive to high heat such as glass to be used as a substrate, and can lend itself to a large amount of annealing treatments on a mass-production scale, yielding consistent annealing quality.

Abstract: There is disclosed a method of producing, in large volume and at low cost, titanium carbide, nitride and carbonitride whiskers, with preferably submicron diameters, to be used as reinforcing material. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Titanium oxide, hydroxide or alkali compounds thereof are mixed with a carbon source with a volatile part which volatiles at temperatures exceeding 500.degree. C. and in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for titanium as well as a catalyst able to dissolve Ti plus C and/or N, such as Ni or Co. The reactant powders are blended in some typical manner, e.g., by using a high speed blender so as to intimately mix them.

Abstract: There are provided a method for fabricating semiconductor nanocrystals which are highly controllable and less variable in density and size, as well as a semiconductor memory device which, with the use of the semiconductor nanocrystals, allows thickness of a insulating film between nanocrystals and channel region to be easily controlled and involves less variations in characteristics such as threshold and programming performance, and which is fast reprogrammable and has nonvolatility. Under a low pressure below atmospheric pressure, an amorphous silicon thin film 3 is deposited on a tunnel insulating film 2 formed on a silicon substrate 1.

Abstract: The invention features a method of continuous crystalline growth. A granular source material is introduced into a hopper. A volume of the granular source material exiting the hopper is disposed on a translationally moving belt. The volume of the granular source material forms an angle of repose with the moving belt. The granular source material disposed on the moving belt is continuously fed into a crucible comprising a melt of the granular source material at a rate based on the angle of repose, the speed of the belt, and the size of the opening of the hopper. A crystalline ribbon is continuously grown by solidifying the melt.

Abstract: Bulk, low impurity aluminum nitride:silicon carbide (AlN:SiC) alloy single crystals are grown by deposition of vapor species containing Al, Si, N and C on a crystal growth interface.

Abstract: Bulk, low impurity aluminum nitride (AlN) single crystals are grown by sublimation or similar deposition techniques at growth rates greater than 0.1 mm/hr.

Abstract: No wide bulk diamond wafer exists at present. A wide diamond-coated wafer is proposed instead of the bulk diamond wafer. Diamond is heteroepitaxially deposited on a convex-distorted non-diamond single crystal substrate by a vapor phase deposition method. In an early step, a negative bias is applied to the substrate. In the case of a Si substrate, an intermediate layer of .beta.-SiC is first deposited on the Si substrate by supplying a low carbon concentration material gas. Then the carbon concentration is raised for making a diamond film. The convex-distorted wafer is stuck to a holder having a shaft which is capable of inclining to the holder. The wafer is pushed to a turn-table of a polishing machine. The convex diamond wafer can fully be polished by inclining the holder to the shaft. A wide distorted mirror wafer of diamond is produced. Fine wire patterns can be made on the diamond mirror wafer by the photolithography.

Abstract: A method for the growth of a SiC single crystal comprisingintroducing a seed crystal of SiC single crystal having an exposed face deviating from the {0001} plane by an angle .alpha..sub.1 of about 60.degree. to about 120.degree., typically about 90.degree. and SiC powder as a raw material into a graphite crucible,elevating the temperature of the SiC powder in an atmosphere of inert gas to a level sufficient for sublimation, meanwhileelevating the temperature of the exposed face of the seed crystal to a level slightly lower than the temperature of the SiC powder, andkeeping the SiC powder and the seed crystal at the specific temperatures for a period enough for a SiC single crystal of the same polytype as the seed crystal to grow to a desired height on the exposed face of the seed crystal.

Abstract: Large diameter single crystals of aluminum nitride (AlN) are grown isotropically by injecting a nitrogen-containing gas into liquid aluminum at elevated temperatures. A seed crystal that is maintained at a temperature below that of the surrounding liquid aluminum is pulled from the melt, while the AlN that is formed in the melt is deposited on the seed crystal. An apparatus for carrying out the method is also disclosed.

Abstract: Metal oxide nanorods and composite materials containing such nanorods. The metal oxide nanorods have diameters between 1 and 200 nm and aspect ratios between 5 and 2000.

Abstract: Bulk, low impurity aluminum nitride (AlN) single crystals are grown by sublimation or similar deposition techniques at growth rates greater than 0.5 mm/hr.

Abstract: There is disclosed a method of producing, in large volumes and at low cost, Ta, Nb, Zr and Hf carbide, nitride or carbonitride whiskers, preferably submicron, having excellent reinforcing properties, suitable as reinforcement in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Oxides of Ta, Nb, Zr and Hf or alkali compounds thereof in an amount to satisfy the stoichiometric requirements of the desired carbide or nitride are mixed with the carbon source along with an alkali and/or alkali earth metal halogenide as a volatilization agent for the metal and a catalyst for the whisker growth such as Ni and/or Co. The reactant powders are blended in some typical manner using a high speed blender so as to intimately mix them. Finally, the starting material is subjected to nitriding, carbonizing or carbonitriding heat treatments in order to produce the desired whiskers.

Abstract: There is disclosed a method of producing whiskers in large volumes and at low cost to be used as reinforcing material. The whiskers are solid solutions between two or more transition metal carbides, nitrides and carbonitrides, (Me.sub.1-X-Y.sub.Me'.sub.X+Y)C.sub.1-Z N.sub.Z, having preferably submicron diameters, where Me' is one or more transition metals other than Me. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Transition metal oxides, hydroxides or alkali compounds thereof are mixed with carbon powder. The carbon source is added in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for the transition metals and a catalyst such as Ni or Co that is able to dissolve transition metals plus C and/or N. The reactant powders are blended so as to intimately mix them.

Abstract: The present invention relates to a method for forming crystal substrates on which can be easily formed spherical crystals which have superior crystal structure and little defect in shape. The present invention also relates to a method for making crystal substrates on which can be easily formed spherical crystals which have little defect in shape and from which impurities have been removed. Projections are formed integrally from a semiconductor crystal base, and flow regulating film is formed to cover the entire outer surface of the crystal base and a base portion of the projections. A heating beam is applied to the tips of the projections, and the end portions of the projections are melted. The surface tension of the melt and the melt regulation by the flow regulating film act to solidify the melt in a spherical shape, thus forming a spherical crystal.

Abstract: A diamond covered member which has a diamond crystal layer is formed by vapor phase synthesis on a surface of a substrate. The process comprises depositing plate-shaped diamond crystals by CVD at a carbon source concentration ranging from 0.01 to 10% at an atomic ratio of oxygen to carbon (O/C) of 0.5.ltoreq.(O/C).ltoreq.1.2 in a starting gas. The crystals may also be deposited by a burning flame method using an oxygen-acetylene flame at a molar ratio of oxygen to acetylene in a main starting gas in the range of 0.9.ltoreq.(O.sub.2 /C.sub.2 H.sub.2).ltoreq.1.0. The plate-shaped diamond crystals are grown to coalesce into a film to form the diamond crystal layer.

Abstract: The presently claimed invention relates to a method of producing, in large volumes and at low cost, transition metal carbide, nitride or carbonitride whiskers, preferably submicron, having excellent reinforcing properties. These whiskers are suitable for use as a reinforcement in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. The basic idea is the use of a carbon source with a volatile part which volatiles at temperatures up to 1000.degree. C. Transition metal oxide or alkali compounds thereof in amounts to satisfy the stoichiometric requirements of the desired carbide or nitride is mixed with the carbon powder along with an alkali metal chloride powder as a volatilization agent for the metal and a catalyst for the whisker growth such as Ni or Co. The reactant powders are blended in some typical manner using a high speed blender so as to intimately mix them.

Abstract: Aluminum nitride whiskers are produced by reducing alumina with carbon in a nitrogen atmosphere, at a temperature of 1800.degree. to 2000.degree. C., in the presence of a growth activator containing a solvent element, according to a process that essentially comprises the step of periodically feeding, through the working area of a horizontal furnace equipped with a graphite heating device, counter to a flow of nitrogen, a graphite container charged with a mixture of alumina, carbon and carbonyl iron, as a growth activator, which is present in an amount capable of implementing the VLS mechanism, the time taken by the container to pass through the working zone being in the range of 20 to 120 minutes.

Abstract: Proposed is a low-cost method for the preparation of a wire-formed crystal of silicon having a diameter of 1 mm or smaller, in which a vertically held starting rod of silicon is melted at one end portion by high-frequency induction heating, a seed crystal is brought into contact with the molten portion and then the seed crystal and the starting silicon rod are pulled apart in the vertical direction at a controlled velocity with a controlled high-frequency power input so that the melt of silicon drawn by the seed crystal is solidified and crystallized into the form of a wire.

Abstract: Disclosed in this invention is a method of preparing a whisker-preform comprising the steps of (a) uniformly dispersing a mixture of silicon microparticles and carbon fibers in the ratio of 4:1 to 8:1 into aluminium alkoxide solution; (b) filtering the dispersion obtained in step (a), dehydrating the filtered material, forming and drying the dehydrated material; and (c) heating the material dried in step (b) at a temperature in the range of 300.degree. to 400.degree. C.

Abstract: A method for producing a single crystal, which comprises (1) placing a metal layer as a pattern at a desired position on the surface of a single crystal substrate, (2) etching the surface of the single crystal substrate around the pattern, and (3) in a raw material gas atmosphere containing an element or elements constituting the single crystal, taking the element or elements in the metal layer at the pattern and permitting a needle-like single crystal to grow perpendicularly.

Abstract: Aluminium borate whiskers by which a composite material having a higher strength than ever is available by definitely suppressing a generation of spinel along the surface of the whiskers are prepared by heating aluminium borate whiskers bearing a r-alumina surface layer in an atmosphere of ammonia gas or ammonia gas and a hydrocarbon gas such that a layer of a nitro-oxide and oxide of aluminium is generated along the surface of the whiskers.

Abstract: A coreless refractory fiber is made by introducing a filament (16) of a starting material into a chemical vapor deposition (CVD) enclosure (10) and then heating the end (21) of the filament by means of a contactless heating source. The source comprises a conducting coil connected to an AC source in the frequency range HF to UHF and with a linear or strip conducting element (110) connected to it such that the ends of the element is adjacent to the end (21) of the filament. The filament (16) is then withdrawn such that refractory material is continuously built up on its end from the chemical vapors in the enclosure to form a coreless retractory fiber. Whiskers of a coreless refractory material may be made by introducing fine particles of a catalyst material to form droplets and then feeding CVD gases to the droplets (30) to thereby promote crystal growth by precipitation from the supersaturated liquid.

Abstract: Described herein is a method and apparatus for continuously growing single crystal whiskers of silicon carbide, silicon nitride, boron carbide and boron nitride by the VLS process under controlled reaction conditions. A growth substrate such as a plate of solid graphite is coated with a suitable VLS catalyst and is conveyed through a tubular furnace, into which is separately introduced two feed gases. The first feed gas contains a cationic suboxide precursor such as silicon monoxide or boron monoxide. The second feed gas contains an anionic precursor compound such as methane or ammonia. The precursor compounds react upon exposure to the catalyst by the VLS process to produce crystalline whiskers. The associated apparatus includes a conveyor assembly that continuously circulates multiple substrate growth plates through the furnace and past a harvesting device which brushes the whiskers from the plates and removes them by vacuum collection. Whiskers of uniform size, shape, and purity are produced.

Abstract: A single-crystal substrate is prepared which has the (100) crystal plane with a step line formed therein by cleaving an MgO single crystal. By evaporating metal onto the cleavage plane, with a mask wire of platinum disposed at a distance from the cleavage plane and extended in a direction across the step line, a pair of metal thin film electrodes separated by a gap are epitaxially grown. By this, a step line corresponding to the cleavage-plane step line is formed in the surface of each of the metal thin film electrodes. Metal is further evaporated onto the metal thin film electrodes at a low rate, by which nano-size thin wires extending along the step lines are grown so that they approach each other and are finally connected to each other.