Provided are a method of producing single crystal AlN, single crystal AlN, and a single crystal AlN production apparatus with which single crystal AlN can be cheaply and continuously produced. The method of producing single crystal AlN includes a melt formation step of heating and melting an alloy to form a melt of the alloy and a deposition step of cooling a portion of the melt and providing a temperature gradient in the melt while causing deposition of single crystal AlN. In the deposition step, a nitrogen-containing gas is brought into contact with a high-temperature portion of the melt and a single crystal AlN seed crystal or a substrate for crystal growth is held in a low-temperature portion of the melt so as to continue to take nitrogen into the melt in the high-temperature portion while causing deposition of single crystal AlN.

The purpose of the present invention is to produce a high-quality SiC single crystal with good reproducibility while avoiding the fluctuations in the solution-contacting position of a seed crystal among production operations. A method for producing a SiC single crystal by bringing a SiC seed crystal supported by a supporting bar into contact with a solution that has been heated by high-frequency induction to thereby grow the SiC single crystal, wherein the supporting bar is born down while applying a magnetic field to the solution to thereby bring the SiC seed crystal into contact with the solution, and subsequently the application of the magnetic field is halted to grow the SiC single crystal.

Provided is a method for producing a SiC single crystal having a concave growth surface and containing no inclusions, even when conducting large diameter crystal growth. This is achieved by a method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the liquid level, to cause crystal growth of a SiC single crystal, wherein the seed crystal holding shaft has a shaft portion and a seed crystal holding portion at the bottom end of the shaft portion, and the ratio of the diameter D1 of the shaft portion to the diameter D2 of the seed crystal holding portion (D1/D2) is no greater than 0.28.

Provided is a method for producing an n-type SiC single crystal, whereby it is possible to grow an n-type SiC single crystal having a low resistivity at a high speed. A method for producing an n-type SiC single crystal by bringing a SiC seed crystal substrate into contact with a SiC solution having such a temperature gradient that the temperature gradually decreases from the inside toward the surface, thereby achieving the crystal growth of the n-type SiC single crystal. The method involves adding a nitride to a raw material for forming the SiC solution or to the SiC solution.

A SiC single crystal comprising no polycrystals, and no cracking other than at the side edges is provided. A method for producing SiC single crystal in which seed crystal held at bottom end face of holding shaft is contacted with SiC solution having temperature gradient to grow SiC single crystal, wherein the contour of the end face of the holding shaft is smaller than the contour of the top face of the seed crystal, the top face of the seed crystal has center section held in contact with the entire surface of the end face of the holding shaft and outer peripheral section that is not in contact with the end face of the holding shaft, and carbon sheet is disposed on the top face of the seed crystal so as to cover at least the outer peripheral section, among the center section and the outer peripheral section.

Embodiments of the present description provide a connecting device. The device comprises a seed crystal support and a seed crystal rod, and the seed crystal support is connected to one end of the seed crystal rod.

Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.

A pressure differential can be applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential can allow release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted through the thickness of the forming wafer. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet can allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

A crystal preparation apparatus (100) and a crystal preparation method (700). The crystal preparation apparatus (100) comprises: a growth cavity (110), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); and a heating assembly (120), used for heating the growth cavity (110). The crystal preparation method (700) comprises: placing a raw material in the growth cavity (110) (710), the growth cavity (110) being internally provided with at least one layer of plate assembly (111); heating the growth cavity (110) by means of the heating assembly (120) so as to melt the raw material into a melt (720); bonding a seed crystal (180) to a seed crystal holder (150) (730); lowering the seed crystal holder (150) to which the seed crystal (180) is bonded, so that the seed crystal (180) is in contact with the melt; and preparing a crystal on the basis of the seed crystal (180) and the melt (750).

Techniques for processing materials in supercritical fluids including processing in a capsule disposed within a high-pressure apparatus enclosure are disclosed. The disclosed techniques are useful for growing crystals of GaN, AlN, InN, and their alloys, including InGaN, AlGaN, and AlInGaN for the manufacture of bulk or patterned substrates, which in turn can be used to make optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation devices, photodetectors, integrated circuits, and transistors.