Abstract: An object of the present invention is to provide a high-quality SiC semiconductor device. In order to solve the above problem, the present invention comprises a method for producing a SiC semiconductor device, comprising a growth step of forming a growth layer on a workpiece comprising SiC single crystals, a device formation step of forming at least a portion of a SiC semiconductor device in the growth layer, and a separation step of separating at least a portion of the SiC semiconductor device from the workpiece.

Abstract: An object of the present invention is to provide a novel technology capable of achieving high-quality SiC seed crystal, SiC ingot, SiC wafer and SiC wafer with an epitaxial film. The present invention, which solves the above object, is a method for producing a SiC seed crystal for growth of a SiC ingot, the method including a heat treatment step of heat-treating a SiC single crystal in an atmosphere containing Si element and C element. As described above, by heat-treating the SiC single crystal in an atmosphere containing the Si element and the C element, it is possible to produce a high-quality SiC seed crystal in which strain and crystal defects are suppressed.

Abstract: The present invention attempts to solve the problem of providing novel technology that makes it possible to grow high-quality semiconductor substrates. In order to solve the abovementioned problem, the present invention provides: a method for producing semiconductor substrates that includes an installation step in which starting substrates and starting materials are installed in an alternating manner and a heating step in which the starting substrates and the starting materials are heated and a growth layer is formed on the starting substrates; and a device for producing the semiconductor substrates. Owing to this configuration, the present invention makes it possible to simultaneously achieve desired growth conditions in each of a plurality of starting substrates and thereby provide novel technology that makes it possible to grow high-quality semiconductor substrates.

Abstract: The present invention addresses the problem of providing a novel SiC substrate production method. The SiC substrate production method according to the present invention comprises an etching step S10 of etching a SiC base substrate 10, a crystal growth step S20 of growing a SiC substrate layer 13 on the SiC base substrate 10 to produce a SiC substrate body 20, and a peeling step S30 of peeling at least a portion of the SiC substrate body 20 to produce a SiC substrate 30, the method being characterized in that each of the etching step S10 and the crystal growth step S20 is a step of arranging the SiC base substrate 10 and a SiC material 40 so as to face each other and heating the SiC base substrate 10 and the SiC material 40 so as to form a temperature gradient between the SiC base substrate 10 and the SiC material 40.

Abstract: The present invention provides a method of manufacturing by the sublimation-recrystallization method more accurately detecting a thermal state of a starting material in a crucible and enabling control of the growth conditions while manufacturing an SiC single crystal.

Abstract: Provided is a SiC single crystal wafer, which is manufactured from a SiC single crystal ingot grown by the sublimation-recrystallization method, and which brings about high device performance and high device manufacture yield when used as a wafer for manufacturing a device. The SiC single crystal wafer has, in a surface thereof, a basal plane dislocation density of 1,000 dislocations per cm2 or less, a threading screw dislocation density of 500 dislocations per cm2 or less, and a Raman index of 0.2 or less. Further provided is a method of manufacturing a SiC single crystal ingot, including controlling heat input from a side surface of the single crystal ingot during growth of a single crystal, to thereby grow the crystal while changes in the temperature distribution of the single crystal ingot are reduced.

Abstract: The present invention provides a method of manufacturing by the sublimation-recrystallization method more accurately detecting a thermal state of a starting material in a crucible and enabling control of the growth conditions while manufacturing an SiC single crystal.

Abstract: Provided are a method by which the degrees of the strains of lattices in a plurality of bulk SiC single crystals can be relatively evaluated, and a reference SiC single crystal to be used in the method.

Abstract: Provided are a method of evaluating an internal stress of a silicon carbide (SiC) single crystal wafer and a method of predicting warpage of the SiC single crystal wafer after completion of polishing by evaluating the internal stress of the wafer. Wavenumber shift amounts of Raman-scattered light are measured at two points within a surface of the SiC single crystal wafer, and the internal stress is evaluated through use of a difference between the wavenumber shift amounts. Also provided is a method of predicting warpage of a silicon carbide single crystal wafer in advance, the silicon carbide single crystal wafer being produced by sublimation-recrystallization method, the method including predicting warpage of a SiC single crystal wafer through use of the evaluation indicator.

Abstract: Provided are a method by which the degrees of the strains of lattices in a plurality of bulk SiC single crystals can be relatively evaluated, and a reference SiC single crystal to be used in the method.

Abstract: Provided are a method of evaluating an internal stress of a silicon carbide (SiC) single crystal wafer and a method of predicting warpage of the SiC single crystal wafer after completion of polishing by evaluating the internal stress of the wafer. Wavenumber shift amounts of Raman-scattered light are measured at two points within a surface of the SiC single crystal wafer, and the internal stress is evaluated through use of a difference between the wavenumber shift amounts. Also provided is a method of predicting warpage of a silicon carbide single crystal wafer in advance, the silicon carbide single crystal wafer being produced by sublimation-recrystallization method, the method including predicting warpage of a SiC single crystal wafer through use of the evaluation indicator.

Abstract: Provided is a SiC single crystal wafer, which is manufactured from a SiC single crystal ingot grown by the sublimation-recrystallization method, and which brings about high device performance and high device manufacture yield when used as a wafer for manufacturing a device. The SiC single crystal wafer has, in a surface thereof, a basal plane dislocation density of 1,000 dislocations per cm2 or less, a threading screw dislocation density of 500 dislocations per cm2 or less, and a Raman index of 0.2 or less. Further provided is a method of manufacturing a SiC single crystal ingot, including controlling heat input from a side surface of the single crystal ingot during growth of a single crystal, to thereby grow the crystal while changes in the temperature distribution of the single crystal ingot are reduced.

Abstract: A rare earth-iron-nitrogen based magnetic material has superior magnetic properties. A method of manufacturing the rare earth-iron-nitrogen based magnetic material controls the decline in the magnetic properties of the material during pulverizing processes, and pulverizes the material to a critical particle dimension for single-domain behavior. The fragility of the material is increased since the material includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W at 0.05-5% atomic percentage. The material is pulverized by a gas current type jet mill. Sample powder injected from a hopper is introduced from a supply mouth to a pulverizing chamber by nitrogen gas spouting from a pressure nozzle, and the powder is then accelerated to acoustic velocity by high pressure nitrogen gas spouting from gliding nozzles. As a result, the powder particles collide with each other.

Abstract: Homogenizing heat-treatment is conducted for changing an ingot containing R (R: Sm or a substance obtained by replacing a part of Sm with one or more kinds of rare earth elements) and T (T: Fe or a substance obtained by replacing a part of Fe with one or more kinds of transition elements) as main component into an alloy ingot mainly containing a R.sub.2 T.sub.17 phase. Next, the above-described alloy ingot is allowed to absorb hydrogen in hydrogen gas in the temperature range of 70.degree. C. to 300.degree. C. and at pressures of 5kgf/cm.sup.2 or more, thus conducting coarse crushing treatment.

Abstract: A magnetic circuit unit for a loud-speaker is provided, in which an adhesion step can be reduced or omitted, magnetic properties can be improved through enhancement of magnetic efficiency, and a durable anti-corrosive treatment can be performed at low price, so that higher performance and lower cost of the loud-speaker can be attained. A method of manufacturing the same is also provided. A top plate has a conical, columnar, truncated conical, or partially spherical hollow part formed on one side whose inner surface is integrated with an anisotropic Nd--Fe--B system magnet under a forming pressure of 100 to 200 kgf/cm.sup.2 through Joule heating by passing a current under compression. The forming die is cooled to a temperature below 100.degree. C. while maintaining the pressure, and the compact is then taken out from the forming die.

Abstract: The foldable chair in accordance with the invention comprises a front frame 1 having a backrest 12 and a front leg 11, a rear frame 2 projectably holding a slide link 22 which is pivotally mounted to the front frame 1 and provided with a rear leg 21 at its down end, and a seat 3 having its side pivotally supported by the rear frame 2 near its rear end and forward of the pivot position at the rear frame 2 pivotally supported by the front frame 1.

Abstract: A rare earth-iron-nitrogen based magnetic material has superior magnetic properties. A method of manufacturing the rare earth-iron-nitrogen based magnetic material controls the decline in the magnetic properties of the material during pulverizing processes, and pulverizes the material to a critical particle dimension for single-domain behavior. The fragility of the material is increased since the material includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W at 0.05-5% atomic percentage. The material is pulverized by a gas current type jet mill. Sample powder injected from a hopper is introduced from a supply mouth to a pulverizing chamber by nitrogen gas spouting from a pressure nozzle, and the powder is then accelerated to acoustic velocity by high pressure nitrogen gas spouting from gliding nozzles. As a result, the powder particles collide with each other.

Abstract: A foldable chair 100 comprises a front frame 1 made of pipe material with a backrest 12 provided at its top end and having a pair of front legs 11 continuously extending downward from the top end; a rear frame 2 made of pipe material having a pair of rear legs 21 continuously extending downward from its top end with a sliding shaft whose top end is pivotally mounted to the front frame 1 and whose bottom end is slidably inserted into the top end of each of the rear legs 21; and a seat 3 having its lateral sides pivotally supported near its rear side by the rear frame 2 and by the front frame i forwardly of the position supported by the rear frame 2; and is characterized by that the front frame 1 being provided with concaves 4 formed therein above the seat 3 in use by plastically transforming the pipe material, that each sliding shaft is provided at its upper end with a pivot member 51 mounted to the concave 4, and that the front and rear frames 1, 2 are so arranged that the axis of the rear leg 21 is generally

Abstract: Homogenizing heat-treatment is conducted for changing an ingot containing R (R: Sm or a substance obtained by replacing a part of Sm with one or more kinds of rare earth elements) and T (T: Fe or a substance obtained by replacing a part of Fe with one or more kinds of transition elements) as main component into an alloy ingot mainly containing a R.sub.2 T.sub.17 phase. Next, the above-described alloy ingot is allowed to absorb hydrogen in hydrogen gas in the temperature range of 70.degree. C. to 300.degree. C., and at pressures of 5 kgf/cm.sup.2 or more, thus conducting coarse crushing treatment.

Abstract: A magnetic circuit component molding device for integrally molding a compound a center yoke with a ring-shaped magnet includes top and bottom press vertically arranged at opposed positions. A ring-shaped magnet is place on a bottom die between top and bottom press. The top and bottom press compress the compound against the ring-shaped magnet ring with a vertical pressure. A holder unit, separated in plural segments, having tapered outer circumferences is provided around the ring-shaped. A holder presser having a tapered inner circumference is mounted on the holder unit as tapered portions thereof are engaged together. A portion of the vertical pressure, when the top press compresses the compound, is transferred by springs 10 to the holder presser, and is amplified by the tapered portions and applied to the outer circumference surface of the ring-shaped magnet by the holder unit.