Embodiments relate to fabricating a wafer including a thin, high-quality single crystal GaN layer serving as a template for formation of additional GaN material. A bulk ingot of GaN material is subjected to implantation to form a subsurface cleave region. The implanted bulk material is bonded to a substrate having lattice and/or Coefficient of Thermal Expansion (CTE) properties compatible with GaN. Examples of such substrate materials can include but are not limited to AlN and Mullite. The GaN seed layer is transferred by a controlled cleaving process from the implanted bulk material to the substrate surface. The resulting combination of the substrate and the GaN seed layer, can form a template for subsequent growth of overlying high quality GaN. Growth of high-quality GaN can take place utilizing techniques such as Liquid Phase Epitaxy (LPE) or gas phase epitaxy, e.g., Metallo-Organic Chemical Vapor Deposition (MOCVD) or Hydride Vapor Phase Epitaxy (HVPE).

A p-type SiC single crystal having lower resistivity than the prior art is provided. This is achieved by a method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the surface, to grow a SiC single crystal, the method comprising: using as the SiC solution a SiC solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al; and contacting a (0001) face of the SiC seed crystal substrate with the SiC solution to grow a SiC single crystal from the (0001) face.

A p-type SiC single crystal having lower resistivity than the prior art is provided. This is achieved by a method for producing a SiC single crystal in which a SiC seed crystal substrate is contacted with a SiC solution having a temperature gradient such that the temperature decreases from the interior toward the surface, to grow a SiC single crystal, the method comprising: using as the SiC solution a SiC solution containing Si, Cr and Al, wherein the Al content is 3 at % or greater based on the total of Si, Cr and Al; and contacting a (0001) face of the SiC seed crystal substrate with the SiC solution to grow a SiC single crystal from the (0001) face.

There is provided a semiconductor substrate including: a sapphire substrate; an intermediate layer formed of gallium nitride with random crystal directions and provided on the sapphire substrate; and at least one or more semiconductor layers each of which is formed of a gallium nitride single crystal and that are provided on the intermediate layer.

There is provided a semiconductor substrate including: a sapphire substrate; an intermediate layer formed of gallium nitride with random crystal directions and provided on the sapphire substrate; and at least one or more semiconductor layers each of which is formed of a gallium nitride single crystal and that are provided on the intermediate layer.

A production method for a group III nitride crystal, the production method includes: preparing a plurality of group III nitride pieces as a plurality of seed crystals on a substrate, and growing a group III nitride crystal by bringing a surface of each of the seed crystals into contact with a melt that comprises at least one group III element selected from gallium, aluminum, and indium, and an alkali metal in an atmosphere comprising nitrogen, and thereby reacting the group III element and the nitrogen in the melt, wherein the step of growing a group III nitride crystal includes: growing a plurality of first group III nitride crystals whose cross-sections each have a triangular shape or a trapezoidal shape, from the plurality of seed crystals; and growing second group III nitride crystals each in a gap among the plurality of first group III nitride crystals.

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.

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 method for growing a crystalline composition, the first crystalline composition may include gallium and nitrogen. The crystalline composition may have an infrared absorption peak at about 3175 cm.sup.1, with an absorbance per unit thickness of greater than about 0.01 cm.sup.1. In one embodiment, the composition ay have an amount of oxygen present in a concentration of less than about 310.sup.18 per cubic centimeter, and may be free of two-dimensional planar boundary defects in a determined volume of the first crystalline composition.

A method for growing a crystalline composition, the first crystalline composition may include gallium and nitrogen. The crystalline composition may have an infrared absorption peak at about 3175 cm.sup.1, with an absorbance per unit thickness of greater than about 0.01 cm.sup.1. In one embodiment, the composition ay have an amount of oxygen present in a concentration of less than about 310.sup.18 per cubic centimeter, and may be free of two-dimensional planar boundary defects in a determined volume of the first crystalline composition.