Abstract: According to the present invention, a complex (M) which is formed by growing a polycrystalline &bgr;-SiC plate 2 having a thickness of 10 &mgr;m or more on the surface of a single crystal &agr;-SiC base material 1 by the PVD method or the thermal CVD method is heat-treated at a temperature of the range of 1,650 to 2,400° C., whereby polycrystals of the polycrystalline cubic &bgr;-SiC plate 2 are transformed into a single crystal, and the single crystal oriented in the same direction as the crystal axis of the single crystal &agr;-SiC base material 1 is grown. As a result, single crystal SiC of high quality which is substantially free from micropipe defects and defects affected by the micropipe defects can be produced easily and efficiently.

Abstract: The single crystal SiC according to the present invention is produced in the following manner. Two complexes M in each of which a polycrystalline film 2 of &bgr;-SiC (or &agr;-SiC) is grown on the surface of a single crystal &agr;-SiC substrate 1 by thermochemical deposition, and the surface 2a of the polycrystalline film 2 is ground so that the smoothness has a surface roughness of 200 angstroms RMS or smaller, preferably 100 to 50 angstroms RMS are subjected to a heat treatment under a state where the complexes are closely fixed to each other via their ground surfaces 2a′, at a temperature of 2,000° C. or higher and in an atmosphere of a saturated SiC vapor pressure, whereby the polycrystalline films 2 of the complexes M are recrystallized to grow a single crystal which is integrated with the single crystal &agr;-SiC substrates 1. Large-size single crystal SiC in which impurities, micropipe defects, and the like do not remain, and which has high quality can be produced with high productivity.

Abstract: An apparatus comprises an Si-disposing section in which solid Si is disposed; a seed-crystal-disposing section in which a seed crystal of SiC is disposed; a synthesis vessel adapted to accommodate the Si-disposing section, the seed-crystal-disposing section, and carbon; heating means adapted to heat the Si-disposing section and the seed-crystal-disposing section; and a control section for transmitting to the heating means a command for heating the Si to an evaporation temperature of Si or higher and heating the seed crystal to a temperature higher than that of Si; wherein the Si evaporated by the heating means is adapted to reach the seed-crystal-disposing section.

Abstract: In single crystal SiC according to the present invention, a single crystal &agr;-SiC substrate and a polycrystalline &bgr;-SiC plate are laminated to each other for fixation, the single crystal &agr;-Sic substrate and the polycrystalline &bgr;-SiC plate are subjected to heat treatment under an inert gas atmosphere and a saturated SiC vapor atmosphere, whereby the single crystallization owing to solid-phase transformation of the polycrystalline &bgr;-SiC plate and a progress of the single crystallization to a surface direction wherein a contact point is regarded as a starting point make a whole surface of layer of the polycrystalline &bgr;-SiC plate grow efficiently into a single crystal integrated with the single crystal &agr;-SiC substrate, whereby it is possible to produce single crystal SiC having high quality with high productivity, which is substantially free from lattice defects and micropipe defects.

Abstract: According to the present invention, a complex (M) which is formed by growing a polycrystalline .beta.-SiC plate 2 on the surface of a single crystal .alpha.-SiC base material 1 by the thermal CVD method is heat-treated at a high temperature of 1,900 to 2,400.degree. C., whereby polycrystals of the polycrystalline cubic .beta.-SiC plate are transformed into a single crystal, so that the single crystal is oriented in the same direction as the crystal axis of the single crystal .alpha.-SiC base material and integrated with the single crystal of the single crystal .alpha.-SiC base material to be largely grown. As a result, single crystal SiC of high quality which has a very reduced number of lattice defects and micropipe defects can be efficiently produced while ensuring a sufficient size in terms of area.

Abstract: According to the present invention, a complex (M) which is formed by stacking a polycrystalline .beta.-SiC plate 2 on the surface of a single crystal .alpha.-SiC base material 1 in a close contact state via a polished face or grown in a layer-like manner by the thermal CVD method is heat-treated in a temperature range of 1,850 to 2,400.degree. C., whereby polycrystals of the polycrystalline cubic .beta.-Sic plate are transformed into a single crystal, and the single crystal oriented in the same direction as the crystal axis of the single crystal .alpha.-SiC base material is grown. As a result, large single crystal SiC of high quality which is free from micropipe defects, lattice defects, generation of grain boundaries due to intrusion of impurities, and the like can be produced easily and efficiently.

Abstract: A complex (M) which is formed by growing a polycrystalline .beta.-SiC plate 4 by the thermal CVD method on crystal orientation faces which are unified in one direction of plural plate-like single crystal .alpha.-SiC pieces 2 that are stacked and closely contacted is subjected to a heat treatment at a temperature in the range of 1,850 to 2,400.degree. C., whereby a single crystal which is oriented in the same direction as the crystal axes of the single crystal .alpha.-SiC pieces 2 is grown from the crystal orientation faces of the single crystal .alpha.-SiC pieces toward the polycrystalline .beta.-SiC plate 4. As a result, single crystal SiC of a high quality in which crystalline nuclei, impurities, micropipe defects, and the like are not substantially generated in an interface can be produced easily and efficiently.

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: A method for heteroepitaxial growth and the device wherein a single crystal ceramic substrate, preferably Y stabilized zirconia, MgAl.sub.2 O.sub.4, A1.sub.2 O.sub.3, 3C--SiC, 6H--SiC or MgO is cut and polished at from about 1.0 to about 10 degrees off axis to produce a substantially flat surface. The atoms on the surface are redistributed on the surface to produce surface steps of at least three lattice spacings. An optional epitaxially grown ceramic buffer layer, preferably AlN or GaN, is then formed on the substrate. Then a layer of semiconductor, preferably SiC, AlN when the buffer layer is used and is not AlN or GaN is grown over the substrate and buffer layer, if used.

Abstract: Low defect density, low impurity bulk single crystals of AlN, SiC and AlN:SiC alloy are produced by depositing appropriate vapor species of Al, Si, N, C on multiple nucleation sites that are preferentially cooled to a temperature less than the surrounding surfaces in the crystal growth enclosure. The vapor species may be provided by subliming solid source material, vaporizing liquid Al, Si or Al--Si or injecting source gases. The multiple nucleation sites may be unseeded or seeded with a seed crystal such as 4 H or 6 H SiC.

Abstract: Pure silicon feedstock is melted and vaporized in a physical vapor transport furnace. In one embodiment the vaporized silicon 46 is reacted with a high purity carbon member 74, such as a porous carbon disc, disposed directly above the silicon. The gaseous species resulting from the reaction are deposited on a silicon carbide seed crystal 50 axially located above the disc, resulting in the growth of monocrystalline silicon carbide 56. In another embodiment, one or more gases, which may include a carbon-containing gas, are additionally introduced at 84 into the furnace, such as into a reaction zone above the disc, to participate in the growth process.

Abstract: The surface 1a of a single crystal .alpha.-SiC substrate 1 is adjusted so as to have a surface roughness equal to or lower than 2,000 angstroms RMS, and preferably equal to or lower than 1,000 angstroms RMS. On the surface 1a of the single crystal .alpha.-SiC substrate 1, a polycrystalline .alpha.-SiC film 2 is grown by thermal CVD to form a complex is placed in a porous carbon container and the carbon container is covered with .alpha.-SiC powder. The complex is subjected to a heat treatment at a temperature equal to or higher than a film growing temperature, i.e., in the range of 1,900 to 2,400.degree. C. in an argon gas flow, whereby single crystal .alpha.-SiC is integrally grown on the single crystal .alpha.-SiC substrate 1 by crystal growth and recrystallization of the polycrystalline .alpha.-SiC film 2. It is possible to stably and efficiently produce single crystal SiC of a large size which has a high quality and in which any crystal nucleus is not generated.

Abstract: Bulk, low impurity silicon carbide single crystals are grown by deposition of vapor species containing silicon and vapor species containing carbon on a crystal growth interface. The silicon source vapor is provided by vaporizing liquid silicon and transporting the silicon vapor to a crystal growth crucible. The carbon vapor species are provided by either a carbon containing source gas (for example, CN) or by flowing the silicon source vapor over or through a solid carbon source, for example flowing the silicon vapor through porous graphite or a bed of graphite particles.

Abstract: A device for epitaxially growing objects of for instance SiC by Chemical Vapor Deposition on a substrate has a first conduit (24) arranged to conduct substantially only a carrier gas to a room (18) receiving the substrate and a second conduit (25) received in the first conduit, having a smaller cross-section than the first conduit and extending in the longitudinal direction of the first conduit with a circumferential space separating it from inner walls of the first conduit. The second conduit is adapted to conduct substantially the entire flow of reactive gases and it ends as seen in the direction of the flows, and emerges into the first conduit at a distance from said room.

Abstract: Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.

Abstract: Method and apparatus for growing semiconductor grade silicon carbide boules (84). Pure silicon feedstock (36) is melted and vaporized. The vaporized silicon is reacted with a high purity carbon-containing gas (64), such as propane, and the gaseous species resulting from the reaction are deposited on a silicon carbide seed crystal (50), resulting in the growth of monocrystalline silicon carbide.

Abstract: A CVD process or a sublimation process for doping an SiC monocrystal uses an organic boron compound whose molecules contain at least one boron atom chemically bonded to at least one carbon atom. Boron trialkyls are preferred organic boron compounds.

Abstract: An easy and low-cost method of producing a large-size and high-purity silicon carbide (SiC) single crystal includes reacting silicon vapor directly with a carbon-containing compound gas under a heated atmosphere (growth space 14) to grow a silicon carbide single crystal (15) on a silicon carbide seed crystal (12), in which the silicon vapor generated from molten silicon (13) is used as a silicon vapor source, and a hydrocarbon gas (9) (e.g., propane gas) is used as the carbon-containing compound gas.

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: A process for growing a single crystal comprises providing a single crystal substrate acting as a seed crystal above a source material in a container, heating the source material in an inert gas atmosphere in the container to form a sublimed source material, and discharging the sublimed source material from the container through a port above the single crystal substrate, to cause the sublimed source material to flow along and in parallel with a surface of the single crystal substrate, and grow a single crystal on the surface of the single crystal substrate.

Abstract: Silicon carbide wafers are prepared for semiconductor epitaxial growth by first lapping a silicon carbide wafer derived from a boule, by placing the wafer in a recess of a metal backed template and moving the wafer over and against a rotating plate. Two different diamond slurry mixtures of progressively smaller diamond grit sizes are sequentially used, along with a lubricant, for a predetermined period of time. The lapping operation is followed by a polishing operation which sequentially utilizes two different diamond slurry mixtures of progressively smaller diamond grit sizes, along with three different apertured pads sequentially applied to a rotatable plate, with the pads being of progressively softer composition. In a preferred embodiment the wafers are cleaned and the templates are changed after each new diamond slurry mixture used.

Abstract: The present invention is directed to a device for heat treatment of objects. It comprises a susceptor for receiving an object in the form of a substrate and a gas mixture fed to the substrate for epitaxial growth of a crystal on said substrate by Chemical Vapor Deposition. The susceptor includes an inner wall and an outer, circumferential wall enclosing the inner wall at a distance therefrom. The inner wall defines a chamber for receiving the object. An enclosed space is formed between the inner and outer wall, and is filled with a powder. The powder is made of SiC, a group III nitride or alloys thereof. Also, for heating the susceptor and thereby also the object, a Rf-field radiator is provided surrounding the susceptor.

Abstract: A method and an apparatus have been developed to deposit heteroepitaxial beta-silicon carbide films on silicon using bias-assisted hot filament chemical vapor deposition (BA-HFCVD). The apparatus includes a graphite plate as the carbon source and the silicon substrate as the silicon source. Hydrogen was the only feeding gas to the system.

Abstract: A process for producing high purity silicon carbide uses a high purity tetraethoxysilane or the like as the silicon source and a novolak-type phenol resin or the like as the carbon source. The process comprises a step of forming silicon carbide in which silicon carbide powder is prepared by calcining a mixture of these sources in a non-oxidizing atmosphere, and a step of post-treating silicon carbide in which the silicon carbide powder thus obtained is treated by heating at a temperature of 2000.degree. to 2100.degree. C. for 5 to 20 minutes at least once while the silicon carbide powder is kept at a temperature of 1700.degree. or higher to lower than 2000.degree. C., to obtain silicon carbide powder having an average particle diameter of 10 to 500 .mu.m and a content of impurity elements of 0.5 ppm or less. The high purity silicon carbide powder is advantageously used as a material for producing an excellent silicon carbide single crystal having a decreased number of crystal defects.

Abstract: Silicon carbide films and microcomponents are grown on silicon substrates at surface temperatures between 900 K and 1700 K via C.sub.60 precursors in a hydrogen-free environment. Selective crystalline silicon carbide growth can be achieved on patterned silicon-silicon oxide samples. Patterned SiC films are produced by making use of the high reaction probability of C.sub.60 with silicon at surface temperatures greater than 900 K and the negligible reaction probability for C.sub.60 on silicon dioxide at surface temperatures less than 1250 K.

Abstract: A silicon carbide semiconductor material; and method of making same, in which a doped film of 3C-silicon carbide is grown heteroepitaxially on a 6H-silicon carbide material. Growth occurs at 1200.degree. C. or less, and produces a heterolayer having a reduced bandgap, and hence reduced contact resistance, but which is fabricatable with the less expensive equipment commonly used to fabricate silicon based semiconductors.

Abstract: A device for epitaxially growing objects by Chemical Vapour Deposition on a substrate (1) comprises a susceptor (4) having a room (6) for receiving the substrate and means (9) for heating the susceptor and thereby the substrate and a gas mixture to be fed to the substrate for said growth. The substrate is arranged close to a first susceptor wall part (7) at least partially delimiting said room. Said heating means is arranged to heat the susceptor to a higher temperature of at least a second wall part (5) delimiting said room thereof and located substantially opposite to said first wall part than the temperature of the first wall part for obtaining a temperature gradient from said second wall part to the substrate and radiative heating thereof by said second wall part. (FIG. 1).

Abstract: Synthetic gemstones having extraordinary brilliance and hardness are formed from large single crystals of relatively low impurity, translucent silicon carbide of a single polytype that are grown in a furnace sublimation system. The crystals are cut into rough gemstones that are thereafter fashioned into finished gemstones. A wide range of colors and shades is available by selective doping of the crystal during growth. A colorless gemstone is produced by growing the crystal undoped in a system substantially free of unwanted impurity atoms.

Abstract: A device for epitaxially growing objects of SiC by Chemical Vapor Deposition on a substrate comprises a substantially cylindrical susceptor having continuous circumferential walls with a substantially uniform thickness surrounding a chamber receiving the substrate, the walls being surrounded by thermal insulation. The circumferential susceptor walls and thereby the substrate and a gas mixture fed to the substrate for the growth are heated to a temperature level in the range of 2000.degree.-2500.degree. C. at which sublimation of the grown material starts to considerably increase. The gas mixture is fed into the susceptor with a composition and at a rate that ensures a positive growth.

Abstract: A method is disclosed for producing epitaxial layers of silicon carbide that are substantially free of micropipe defects. The method comprises growing an epitaxial layer of silicon carbide on a silicon carbide substrate by liquid phase epitaxy from a melt of silicon carbide in silicon and an element that enhances the solubility of silicon carbide in the melt. The atomic percentage of that element predominates over the atomic percentage of silicon in the melt. Micropipe defects propagated by the substrate into the epitaxial layer are closed by continuing to grow the epitaxial layer under the proper conditions until the epitaxial layer has a thickness at which micropipe defects present in the substrate are substantially no longer reproduced in the epitaxial layer, and the number of micropipe defects in the epitaxial layer is substantially reduced.

Abstract: A silicon carbide growth container for placement into a crystal growing furnace. The growth container has a liner of pyrolytic graphite which seals the inside of the container and allows for easy removal of the grown silicon carbide crystal.

Abstract: Active semiconductor devices including heterojunction diodes and thin film transistors are formed by PECVD deposition of a boron carbide thin film on an N-type substrate. The boron to carbon ratio of the deposited material is controlled so that the film has a suitable band gap energy. Boron carbides such as B.sub.4.7 C, B.sub.7.2 C and B.sub.19 C have suitable band gap energies between 0.8 and 1.7 eV. The stoichiometry of the film can be selected by varying the partial pressure of precursor gases, such as nido pentaborane and methane. The precursor gas or gases are energized, e.g., in a plasma reactor. The heterojunction diodes retain good rectifying properties at elevated temperature, e.g., up to 400.degree. C.

Abstract: A substrate for use in semiconductor devices, fabricated of silicon carbide and having a resistivity of greater than 1500 Ohm-cm. The substrate being characterized as having deep level impurities incorporated therein, wherein the deep level elemental impurity comprises one of a selected heavy metal, hydrogen, chlorine and fluorine. The selected heavy metal being a metal found in periodic groups IIIB, IVB, VB, VIB, VIIB, VIIIB, IB and IIB.

Abstract: .beta.-silicon carbide which is optically transmitting in the visible and infrared regions is produced by chemical vapor deposition. Deposition conditions are temperatures within a 1400.degree.-1500.degree. C. range, pressure 50 torr or less, H.sub.2 /methyltrichlorosilane molar ratios of 4-30 and a deposition rate of 1 .mu.m or less.

Abstract: A SOI substrate has a first insulating film formed on a semiconductor substrate. A first opening is formed thereon and a dummy layer is formed on the first opening and the first insulating film. A second opening is formed in the dummy layer and a second insulating film is formed and the dummy layer is removed by etching through the third opening to form a cavity. A semiconductor crystal layer is epitaxially grown within the cavity with use of the semiconductor substrate as a seed. The second insulating film is then removed from the semiconductor crystal layer.

Abstract: A semiconductor device is manufactured by forming an epitaxial layer (22) insulated from a silicon substrate (2), and forming a device in the epitaxial layer (22). On the semiconductor substrate (2), a silicon dioxide layer (4) is formed (FIG. 2A). Then the silicon dioxide layer (4) is provided with openings (14) (FIG. 2D). Silicon carbide is grown until it protrudes from the openings (14) to thereby form a silicon carbide seed crystal layer (16) (FIG. 2E). Next, oxidation is carried out, allowing a field oxide layer (20) to be connected at the portion under the openings (14) and the silicon carbide seed crystal layer (16) to be insulated from the silicon substrate (2). Thereafter, epitaxial growth is effected from the silicon carbide seed crystal layer (16). The growth is stopped before silicon grown layers (22) connect to one another, thus obtaining epitaxially grown layers (22) having regions which are separate from one another. The MOS device is formed in this epitaxially grown layer (22).

Abstract: A method for epitaxially growing a-axis .alpha.-SiC on an a-axis substrate is provided. A section is formed from the SiC crystal by making a pair of parallel cuts in the crystal. Each of these cuts is parallel to the c-axis of the crystal. The resulting section formed from the crystal has opposing a-face surfaces parallel to the c-axis of the crystal. A gas mixture having hydrocarbon and silane is passed over one of the a-face surfaces of the section. The hydrocarbon and silane react on this a-face surface to form an epitaxial layer of SiC. Preferably, the SiC is grown at a temperature of approximately 1450.degree. C.

Abstract: A method of controlling the amount of impurity incorporation in a crystal grown by a chemical vapor deposition process. Conducted in a growth chamber, the method includes the controlling of the concentration of the crystal growing components in the growth chamber to affect the demand of particular growth sites within the growing crystal thereby controlling impurity incorporation into the growth sites.

Abstract: A method of growing a first SiC single crystal on a seed crystal including a second SiC single crystal, comprises the steps of setting a SiC source material at an initial temperature, growing the first SiC single crystal on the seed crystal including the second SiC single crystal at a temperature lower than the initial temperature of the source material and gradually decreasing the source material temperature from the initial temperature during at least a predetermined period during the growing step.

Abstract: There is provided a method of producing a high-quality n-type, 6H silicon carbide single crystal with good reproducibility. A silicon carbide single crystal substrate having a growth orientation of <0001>, as a seed crystal, is mounted to an inner surface of a cover of a graphite crucible. A source material includes a high-purity silicon carbide powder having an impurity proportion of not more than 1 ppm and an aluminum powder of 50 ppm relative to the silicon carbide powder. The source material is loaded into the graphite crucible. The graphite crucible is closed with a seed crystal-mounted cover placed in a double quartz tube. Ar gas and N.sub.2 gas are caused to flow in the double quartz tube. Temperature of the silicon carbide powder and aluminum powder is controlled to 2300.degree. C., and temperature of the silicon carbide single crystal substrate to 2200.degree. C.; and interior of the double quartz tube is controlled to 30 torr.

Abstract: Beta-silicon carbide whiskers of superior uniformity can be formed, either singly or in-situ in a matrix, by heating a source for silicon with a source of carbon (greater than 0 percent but less than or equal to about 60 percent of stoichiometric, with respect to the silicon source) in the presence of a titanium-containing catalyst, such as titanocene dichloride. Advantageously, the titanium catalyst can be applied by drying a solution of the titanium catalyst on the carbon and silicon sources. The titanium, carbon and silicon sources are then heated together, preferably to between about 1800.degree. C. and about 1850.degree. C., resulting in a product containing high quality beta-silicon carbide whiskers.

Abstract: This invention is a method for the controlled growth of single-crystal semiconductor-device-quality films of SiC polytypes on vicinal (0001) SiC wafers with low tilt angles. Both homoepitaxial and heteroepitaxial SiC films can be produced on the same wafer. In particular, 3C-SiC and 6H-SiC films can be produced within selected areas of the same 6H-SiC wafer.

Abstract: A method of synthesizing a large area, single crystalline, semiconductor wafer in which the semiconductor is grown on a substrate having a lower melting temperature and higher specific gravity than the overlying semiconductor. The substrate is disposed within an open container or holder having a drain plug. First, a very thin layer of semiconductor is grown on the substrate. Then, the temperature is raised to melt the substrate and anneal the very thin layer of semiconductor. Next, growth of the semiconductor film now floating on the molten substrate is resumed until the desired thickness is obtained. Then, the molten substrate is drained from the holder, the temperature lowered to room temperature, and the nascent large area semiconductor wafer removed from the holder.

Abstract: A method of making pure fibers from a parent material utilizing laser energy. A short wavelength laser is used to achieve a diffraction limited focal spot diameter that is smaller than the diameter of the growing fiber. Focused laser beam convergence is used to obtain a fiber growth rate that depends on the fiber tip portion such that the fiber growth rate achieves a value equal to the controlled fiber pulling rate. The present invention achieves vapor-liquid-solid growth of single crystal silicon fibers and whiskers from silane gas and permits the use of other materials in the production of fibers by the vapor-liquid-solid process. The method provides an increase in the allowable ambient pressure and growth temperature and a large and more energy efficient growth velocity as compared to carbon dioxide based laser beam technology.

Abstract: Thin films of cubic boron nitride carbide are provided on an underlying silicon substrate. The cubic boron nitride carbide films are deposited using laser ablation methods. The boron nitride film has a crystallographic lattice constant which can be varied depending upon the desired film composition and processing parameters. Preferably, the resulting thin film composition is characterized by a chemical formula of (BN).sub.1-x C.sub.x where x is about 0.2. The resulting films are particularly suitable for wear resistance and semiconducting applications over a wide range of temperatures.