Abstract: An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10?5 ? or less is observed.

Abstract: The method for producing a group III nitride semiconductor crystal comprises preparing a seed crystal having a non-polar plane followed by growing a group III nitride semiconductor from the non-polar plane in a vapor phase, wherein the growing includes growing the group III nitride semiconductor so as to extend in the +C-axis direction of the seed crystal. A group III-V nitride semiconductor crystal having high quality and a large-area non-polar plane can be obtained by the method.

Abstract: A periodic table Group 13 metal nitride crystals grown with a non-polar or semi-polar principal surface have numerous stacking faults. The purpose of the present invention is to provide a period table Group 13 metal nitride crystal wherein the occurrence of stacking faults of this kind are suppressed. The present invention achieves the foregoing by a periodic table Group 13 metal nitride crystal being characterized in that, in a Qx direction intensity profile that includes a maximum intensity and is derived from an isointensity contour plot obtained by x-ray reciprocal lattice mapping of (100) plane of the periodic table Group 13 metal nitride crystal, a Qx width at 1/300th of peak intensity is 6×10?4 rlu or less.

Abstract: Provided is a base substrate with which a Group-III nitride crystal having a large area and a large thickness can be grown while inhibiting crack generation. A single-crystal substrate for use in growing a Group-III nitride crystal thereon, which satisfies the following expression (1), wherein Z1 (?m) is an amount of warpage of physical shape in a growth surface of the single-crystal substrate and Z2 (?m) is an amount of warpage calculated from a radius of curvature of crystallographic-plane shape in a growth surface of the single-crystal substrate: ?40<Z2/Z1<?1: Expression (1).

Abstract: A method of growing high-quality, group-III nitride, bulk single crystals. The group III-nitride bulk crystal is grown in an autoclave in supercritical ammonia using a source material or nutrient that is a group III-nitride polycrystals or group-III metal having a grain size of at least 10 microns or more and a seed crystal that is a group-III nitride single crystal. The group III-nitride polycrystals may be recycled from previous ammonothermal process after annealing in reducing gas at more then 600° C. The autoclave may include an internal chamber that is filled with ammonia, wherein the ammonia is released from the internal chamber into the autoclave when the ammonia attains a supercritical state after the heating of the autoclave, such that convection of the supercritical ammonia transfers source materials and deposits the transferred source materials onto seed crystals, but undissolved particles of the source materials are prevented from being transferred and deposited on the seed crystals.

Abstract: Provided is a base substrate with which a Group-III nitride crystal having a large area and a large thickness can be grown while inhibiting crack generation. A single-crystal substrate for use in growing a Group-III nitride crystal thereon, which satisfies the following expression (1), wherein Z1 (?m) is an amount of warpage of physical shape in a growth surface of the single-crystal substrate and Z2 (?m) is an amount of warpage calculated from a radius of curvature of crystallographic-plane shape in a growth surface of the single-crystal substrate: ?40<Z2/Z1<?1: Expression (1).

Abstract: A method of growing high-quality, group-III nitride, bulk single crystals. The group III-nitride bulk crystal is grown in an autoclave in supercritical ammonia using a source material or nutrient that is a group III-nitride polycrystals or group-III metal having a grain size of at least 10 microns or more and a seed crystal that is a group-III nitride single crystal. The group III-nitride polycrystals may be recycled from previous ammonothermal process after annealing in reducing gas at more then 600° C. The autoclave may include an internal chamber that is filled with ammonia, wherein the ammonia is released from the internal chamber into the autoclave when the ammonia attains a supercritical state after the heating of the autoclave, such that convection of the supercritical ammonia transfers source materials and deposits the transferred source materials onto seed crystals, but undissolved particles of the source materials are prevented from being transferred and deposited on the seed crystals.

Abstract: Provided is a high-quality Group III nitride crystal of excellent processability. A Group III nitride crystal is produced by forming a film is composed of an oxide, hydroxide and/or oxyhydroxide containing a Group III element by heat-treating a Group III nitride single crystal at 1000° C. or above, and removing the film.

Abstract: The method for producing a group III nitride semiconductor crystal comprises preparing a seed crystal having a non-polar plane followed by growing a group III nitride semiconductor from the non-polar plane in a vapor phase, wherein the growing includes growing the group III nitride semiconductor so as to extend in the +C-axis direction of the seed crystal. A group III-V nitride semiconductor crystal having high quality and a large-area non-polar plane can be obtained by the method.

Abstract: A method for efficiently producing a plate-like nitride semiconductor crystal having the desired principal plane in a simple method is provided. A raw material gas is fed to a seed crystal in which a ratio (L/W) of length L in a longitudinal direction and maximum width W, of a plane of projection obtained by projecting a crystal growth face on the seed crystal in a growth direction is from 2 to 400, and the maximum width W is 5 mm or less, thereby growing a plate-like semiconductor crystal on the seed crystal.

Abstract: The method for producing a group III nitride semiconductor crystal comprises preparing a seed crystal having a non-polar plane followed by growing a group III nitride semiconductor from the non-polar plane in a vapor phase, wherein the growing includes growing the group III nitride semiconductor so as to extend in the +C-axis direction of the seed crystal. A group III-V nitride semiconductor crystal having high quality and a large-area non-polar plane can be obtained by the method.

Abstract: Provided is a base substrate with which a Group-III nitride crystal having a large area and a large thickness can be grown while inhibiting crack generation. A single-crystal substrate for use in growing a Group-III nitride crystal thereon, which satisfies the following expression (1), wherein Z1 (?m) is an amount of warpage of physical shape in a growth surface of the single-crystal substrate and Z2 (?m) is an amount of warpage calculated from a radius of curvature of crystallographic-plane shape in a growth surface of the single-crystal substrate: ?40<Z2/Z1<?1: Expression (1).

Abstract: The method for producing a group III nitride semiconductor crystal of the invention comprises a step of preparing a seed crystal having a non-polar plane followed by growing a group III nitride semiconductor from the non-polar plane in a vapor phase, wherein the growing step includes growing the group III nitride semiconductor so as to extend in the +C-axis direction of the seed crystal. A group III-V nitride semiconductor crystal having high quality and a large-area non-polar plane can be obtained by the method.

Abstract: A production process for a nitride semiconductor crystal, comprising growing a semiconductor layer on a seed substrate to obtain a nitride semiconductor crystal, wherein the seed substrate comprises a plurality of seed substrates made of the same material, at least one of the plurality of seed substrates differs in the off-angle from the other seed substrates, and a single semiconductor layer is grown by disposing the plurality of seed substrates in a semiconductor crystal production apparatus, such that when the single semiconductor layer is grown on the plurality of seed substrates, the off-angle distribution in the single semiconductor layer becomes smaller than the off-angle distribution in the plurality of seed substrates.

Abstract: A Group-III nitride semiconductor substrate having a flat surface with a dangling bond density of higher than 14.0 nm?2 is produced by cleaning the surface having a dangling bond density of higher than 14.0 nm?2 with a cleaning agent containing an ammonium salt.

Abstract: A Group-III nitride semiconductor substrate having a flat surface with a dangling bond density of higher than 14.0 nm?2 is produced by cleaning the surface having a dangling bond density of higher than 14.0 nm?2 with a cleaning agent containing an ammonium salt.

Abstract: A method for efficiently producing a plate-like nitride semiconductor crystal having the desired principal plane in a simple method is provided. A raw material gas is fed to a seed crystal in which a ratio (L/W) of length L in a longitudinal direction and maximum width W, of a plane of projection obtained by projecting a crystal growth face on the seed crystal in a growth direction is from 2 to 400, and the maximum width W is 5 mm or less, thereby growing a plate-like semiconductor crystal on the seed crystal.

Abstract: A Group-III nitride semiconductor substrate having a flat surface with a dangling bond density of higher than 14.0 nm?2 is produced by cleaning the surface having a dangling bond density of higher than 14.0 nm?2 with a cleaning agent containing an ammonium salt.

Abstract: A Group-III nitride semiconductor substrate having a flat surface with a dangling bond density of higher than 14.0 nm?2 is produced by cleaning the surface having a dangling bond density of higher than 14.0 nm?2 with a cleaning agent containing an ammonium salt.

Abstract: A method of growing high-quality, group-III nitride, bulk single crystals. The group III-nitride bulk crystal is grown in an autoclave in supercritical ammonia using a source material or nutrient that is a group III-nitride polycrystals or group-III metal having a grain size of at least 10 microns or more and a seed crystal that is a group-III nitride single crystal. The group III-nitride polycrystals may be recycled from previous ammonothermal process after annealing in reducing gas at more then 600° C. The autoclave may include an internal chamber that is filled with ammonia, wherein the ammonia is released from the internal chamber into the autoclave when the ammonia attains a supercritical state after the heating of the autoclave, such that convection of the supercritical ammonia transfers source materials and deposits the transferred source materials onto seed crystals, but undissolved particles of the source materials are prevented from being transferred and deposited on the seed crystals.