It is provided a layer of a crystal of a nitride of a group 13 element selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof, and the layer includes an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, and the high-luminance light-emitting part has a portion extending along an m-plane of the crystal of the nitride of the group 13 element, in the case that the upper surface is observed by cathode luminescence. The upper surface has an arithmetic average roughness Ra of 0.05 nm or more and 1.0 nm or less.

The seed substrate comprises a base substrate and a base layer comprising a Group III nitride semiconductor formed on the base substrate, which has a high dislocation density region and a low dislocation density region. The planar pattern of the high dislocation density region is a honeycomb pattern. A hollow exists between the base substrate and the low dislocation density region. The object layer is grown through a flux method using the seed substrate. The high dislocation density region is melted back at an initial stage of crystal growth, and thereafter, the object layer is grown on the top surface of the low dislocation density region. A cavity remains between the high dislocation density region and the object layer. The presence of the cavity and the hollow makes easy to peel the object layer from the seed substrate.

The seed substrate comprises a base substrate and a base layer comprising a Group III nitride semiconductor formed on the base substrate, which has a high dislocation density region and a low dislocation density region. The planar pattern of the high dislocation density region is a honeycomb pattern. A hollow exists between the base substrate and the low dislocation density region. The object layer is grown through a flux method using the seed substrate. The high dislocation density region is melted back at an initial stage of crystal growth, and thereafter, the object layer is grown on the top surface of the low dislocation density region. A cavity remains between the high dislocation density region and the object layer. The presence of the cavity and the hollow makes easy to peel the object layer from the seed substrate.

The present invention relates to a silicon-based molten composition for forming a SiC single crystal by a solution method, the composition containing silicon, carbon, and a metal satisfying 0.70Csisol1.510 with respect to a solubility parameter (Csisol) defined by the following Equation (1):
Csisol=AB+12Equation (1) wherein, A is first energy (A) of a first evaluation lattice containing silicon atoms, carbon atoms, and metal atoms, in a silicon crystal lattice containing the metal and the carbon; B is second energy (B) of a second evaluation lattice containing silicon atoms and metal atoms, in a silicon crystal lattice containing the metal; 1 is 5.422 as a constant value, and 2 is 9.097 as a constant value.

The present invention relates to a silicon-based molten composition for forming a SiC single crystal by a solution method, the composition containing silicon, carbon, and a metal satisfying 0.70Csisol1.510 with respect to a solubility parameter (Csisol) defined by the following Equation (1):
Csisol=AB+12Equation (1) wherein, A is first energy (A) of a first evaluation lattice containing silicon atoms, carbon atoms, and metal atoms, in a silicon crystal lattice containing the metal and the carbon; B is second energy (B) of a second evaluation lattice containing silicon atoms and metal atoms, in a silicon crystal lattice containing the metal; 1 is 5.422 as a constant value, and 2 is 9.097 as a constant value.

A nitride single crystal having high crystallinity is provided. A nitride single crystal 10 has a wurtzite crystal structure, and a content of boron is 0.5 ppm by mass or more and 251 ppm by mass or less.

In a method for manufacturing a group 13 nitride crystal, a seed crystal made of a group 13 nitride crystal is arranged in a mixed melt containing an alkali metal and a group 13 element, and nitrogen is supplied to the mixed melt to grow the group 13 nitride crystal on a principal plane of the seed crystal. The seed crystal is manufactured by vapor phase epitaxy. At least a part of contact members coming into contact with the mixed melt in a reaction vessel accommodating the mixed melt is made of Al.sub.2O.sub.3. An interface layer having a photoluminescence emission peak whose wavelength is longer than the wavelength of a photoluminescence emission peak of the grown group 13 nitride crystal is formed between the seed crystal and the grown group nitride crystal.

A low-resistance p-type SiC single crystal containing no inclusions is provided. 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 a temperature of the SiC solution decreases from an interior of the SiC solution toward a surface of the SiC solution, to grow the SiC single crystal, wherein the SiC solution comprises Si, Cr, Al and B, and wherein the Al is comprised in the SiC solution in an amount of 10 at % or greater, based on the total of the Si, Cr, Al and B, and the B is comprised in the SiC solution in an amount of greater than 0.00 at % and no greater than 1.00 at %, based on the total of the Si, Cr, Al and B.

Provided is a SiC single crystal that has a large growth thickness and contains no inclusions. A SiC single crystal grown by a solution process, wherein the total length M of the outer peripheral section formed by the {1-100} faces on the {0001} growth surface of the SiC single crystal, and the length P of the outer periphery of the growth surface of the SiC single crystal, satisfy the relationship M/P0.70, and the length in the growth direction of the SiC single crystal is 2 mm or greater.

Provided is a SiC single crystal that has a large growth thickness and contains no inclusions. A SiC single crystal grown by a solution process, wherein the total length M of the outer peripheral section formed by the {1-100} faces on the {0001} growth surface of the SiC single crystal, and the length P of the outer periphery of the growth surface of the SiC single crystal, satisfy the relationship M/P0.70, and the length in the growth direction of the SiC single crystal is 2 mm or greater.