A method for manufacturing a silicon carbide single crystal includes: packing a silicon carbide source material into a crucible, the silicon carbide source material having a flowability index of not less than 70 and not more than 100; and sublimating the silicon carbide source material by heating the silicon carbide source material.

A method for manufacturing a silicon carbide single crystal includes: packing a silicon carbide source material into a crucible, the silicon carbide source material having a flowability index of not less than 70 and not more than 100; and sublimating the silicon carbide source material by heating the silicon carbide source material.

Proposed is a manufacturing method of a high-quality β-Ga.sub.2O.sub.3 thin film using a high-quality β-Ga.sub.2O.sub.3 thin film manufacturing apparatus based on halide vapor phase epitaxy (HVPE) growth. The apparatus includes a reaction gas generating unit in which a chlorine-based gas and Ga in a source zone react to generate GaClx, a dopant gas supply unit, an additional chlorine-based gas supply unit for supplying an additional chlorine-based gas in a source tube, oxygen-based gas supply units, and a susceptor unit supporting a substrate on which a Ga.sub.2O.sub.3 thin film is to be formed. During the epitaxial growth, the additional hydrogen chloride (HCl) gas is supplied to reduce the pre-reaction between precursors, and a movement distance to the susceptor can is increased to increase growth rate and growth speed to control the crystallinity. Thus, high-quality epitaxial growth and a high production yield can be achieved.

Proposed is a manufacturing method of a high-quality β-Ga.sub.2O.sub.3 thin film using a high-quality β-Ga.sub.2O.sub.3 thin film manufacturing apparatus based on halide vapor phase epitaxy (HVPE) growth. The apparatus includes a reaction gas generating unit in which a chlorine-based gas and Ga in a source zone react to generate GaClx, a dopant gas supply unit, an additional chlorine-based gas supply unit for supplying an additional chlorine-based gas in a source tube, oxygen-based gas supply units, and a susceptor unit supporting a substrate on which a Ga.sub.2O.sub.3 thin film is to be formed. During the epitaxial growth, the additional hydrogen chloride (HCl) gas is supplied to reduce the pre-reaction between precursors, and a movement distance to the susceptor can is increased to increase growth rate and growth speed to control the crystallinity. Thus, high-quality epitaxial growth and a high production yield can be achieved.

A method of fabricating plates of super-hard material and cutting techniques suitable for such a method. A method of fabricating a plate (14) of super-hard material, the method comprising: • providing a substrate (4) have a lateral dimension of at least 40 mm; • growing a layer of super-hard material on the substrate (4) using a chemical vapour deposition process; and • slicing one or more plates (14) of super-hard material from the substrate using a collimated cutting beam (8), the or each plate of super-hard material (14) having a lateral dimension of at least 40 mm, wherein the collimated cutting beam (8) is collimated with a half angle divergence of no more than 5 degrees.

A method of fabricating plates of super-hard material and cutting techniques suitable for such a method. A method of fabricating a plate (14) of super-hard material, the method comprising: • providing a substrate (4) have a lateral dimension of at least 40 mm; • growing a layer of super-hard material on the substrate (4) using a chemical vapour deposition process; and • slicing one or more plates (14) of super-hard material from the substrate using a collimated cutting beam (8), the or each plate of super-hard material (14) having a lateral dimension of at least 40 mm, wherein the collimated cutting beam (8) is collimated with a half angle divergence of no more than 5 degrees.

A high-pressure high-temperature, HPHT, diamond tool piece and a method of producing an HPHT diamond tool piece. At least a portion of the HPHT diamond tool piece comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%. The method includes irradiating an HPHT diamond material to introduce vacancies in the diamond crystal lattice, annealing the HPHT diamond material such that at least a portion of the HPHT diamond material comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%, and processing the HPHT diamond material to form an HPHT diamond tool piece.

A high-pressure high-temperature, HPHT, diamond tool piece and a method of producing an HPHT diamond tool piece. At least a portion of the HPHT diamond tool piece comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%. The method includes irradiating an HPHT diamond material to introduce vacancies in the diamond crystal lattice, annealing the HPHT diamond material such that at least a portion of the HPHT diamond material comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%, and processing the HPHT diamond material to form an HPHT diamond tool piece.

A method for producing a single crystal includes: bringing a seed crystal into contact with a dopant-added melt, in which a red phosphorus is added to a silicon melt, such that a resistivity of the single crystal is 0.9 mΩ.Math.cm or less and subsequently pulling up the seed crystal, to form a straight body of the single crystal; and withdrawing the single crystal from the dopant-added melt in a state that a temperature of an upper end of the straight body is 590 degrees C. or more.

A method for producing a single crystal includes: bringing a seed crystal into contact with a dopant-added melt, in which a red phosphorus is added to a silicon melt, such that a resistivity of the single crystal is 0.9 mΩ.Math.cm or less and subsequently pulling up the seed crystal, to form a straight body of the single crystal; and withdrawing the single crystal from the dopant-added melt in a state that a temperature of an upper end of the straight body is 590 degrees C. or more.