Abstract: Group-III nitride crystal composites made up of especially processed crystal slices, cut from III-nitride bulk crystal, whose major surfaces are of {1-10±2}, {11-2±2}, {20-2±1} or {22-4±1} orientation, disposed adjoining each other sideways with the major-surface side of each slice facing up, and III-nitride crystal epitaxially present on the major surfaces of the adjoining slices, with the III-nitride crystal containing, as principal impurities, either silicon atoms or oxygen atoms. With x-ray diffraction FWHMs being measured along an axis defined by a <0001> direction of the substrate projected onto either of the major surfaces, FWHM peak regions are present at intervals of 3 to 5 mm width. Also, with threading dislocation density being measured along a <0001> direction of the III-nitride crystal substrate, threading-dislocation-density peak regions are present at the 3 to 5 mm intervals.

Abstract: Group-III nitride crystal composites made up of especially processed crystal slices, cut from III-nitride bulk crystal, whose major surfaces are of {1-10±2}, {11-2±2}, {20-2±1} or {22-4±1} orientation, disposed adjoining each other sideways with the major-surface side of each slice facing up, and III-nitride crystal epitaxially present on the major surfaces of the adjoining slices, with the III-nitride crystal containing, as principal impurities, either silicon atoms or oxygen atoms. With x-ray diffraction FWHMs being measured along an axis defined by a <0001> direction of the substrate projected onto either of the major surfaces, FWHM peak regions are present at intervals of 3 to 5 mm width. Also, with threading dislocation density being measured along a <0001> direction of the III-nitride crystal substrate, threading-dislocation-density peak regions are present at the 3 to 5 mm intervals.

Abstract: Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1×1016 cm?3 to 4×1019 cm?3 or a silicon-atom concentration of 6×1014 cm?3 to 5×1018 cm?3, and by having a carrier concentration of 1×1016 cm?3 to 6×1019 cm?3.

Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.

Abstract: Group-III nitride crystal composites made up of especially processed crystal slices, cut from III-nitride bulk crystal, whose major surfaces are of {1-10±2}, {11-2±2}, {20-2±1} or {22-4±1} orientation, disposed adjoining each other sideways with the major-surface side of each slice facing up, and III-nitride crystal epitaxially present on the major surfaces of the adjoining slices, with the III-nitride crystal containing, as principal impurities, either silicon atoms or oxygen atoms.

Abstract: Affords Group-III nitride single-crystal ingots and III-nitride single-crystal substrates manufactured utilizing the ingots, as well as methods of manufacturing III-nitride single-crystal ingots and methods of manufacturing III-nitride single-crystal substrates, wherein the incidence of cracking during length-extending growth is reduced. Characterized by including a step of etching the edge surface of a base substrate, and a step of epitaxially growing onto the base substrate hexagonal-system III-nitride monocrystal having crystallographic planes on its side surfaces. In order to reduce occurrences of cracking during length-extending growth of the ingot, depositing-out of polycrystal and out-of-plane oriented crystal onto the periphery of the monocrystal must be controlled.

Abstract: A method for producing a Group III nitride crystal includes the steps of cutting a plurality of Group III nitride crystal substrates 10p and 10q having a major surface from a Group III nitride bulk crystal 1, the major surfaces 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20?21}, {20?2?1}, {22?41}, and {22?4?1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the major surfaces 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a Group III nitride crystal 20 on the major surfaces 10pm and 10qm of the substrates 10p and 10q.

Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A GaN substrate is stored within an atmosphere in which the oxygen concentration is not greater than 15 vol. % and the water-vapor concentration is not greater than 20 g/m3. The GaN substrate (1) has a planar first principal face (1m), and in an arbitrary point (P) along the first principal face (1m) and separated 3 mm or more from the outer edge thereof, the GaN substrate's plane orientation has an off-inclination angle ?? of ?10° or more, 10° or less with respect to the plane orientation of an arbitrarily designated crystalline plane (1a) that is inclined 50° or more, 90° or less with respect to a plane (1c), being either the (0001) plane or the (000 1) plane, through the arbitrary point. This enables storing GaN substrates whose principal-face plane orientation is other than (0001) or (000 1), making available GaN substrates with which semiconductor devices of favorable properties can be manufactured.

Abstract: Group-III nitride crystal composites made up of especially processed crystal slices, cut from III-nitride bulk crystal, whose major surfaces are of {1-10±2}, {11-2±2}, {20-2±1} or {22-4±1} orientation, disposed adjoining each other sideways with the major-surface side of each slice facing up, and III-nitride crystal epitaxially present on the major surfaces of the adjoining slices, with the III-nitride crystal containing, as principal impurities, either silicon atoms or oxygen atoms.

Abstract: Provided is a method of manufacturing III-nitride crystal having a major surface of plane orientation other than {0001}, designated by choice, the III-nitride crystal manufacturing method including: a step of slicing III-nitride bulk crystal through a plurality of planes defining a predetermined slice thickness in the direction of the designated plane orientation, to produce a plurality of III-nitride crystal substrates having a major surface of the designated plane orientation; a step of disposing the substrates adjoining each other sideways in a manner such that the major surfaces of the substrates parallel each other and such that any difference in slice thickness between two adjoining III-nitride crystal substrates is not greater than 0.1 mm; and a step of growing III-nitride crystal onto the major surfaces of the substrates.

Abstract: A group III nitride composite substrate includes a support substrate and a group III nitride film. A ratio st/mt of a standard deviation st of the thickness of the group III nitride film, to a mean value mt of the thickness thereof is 0.001 or more and 0.2 or less, and a ratio so/mo of a standard deviation so of an absolute value of an off angle between a main surface of the group III nitride film and a plane of a predetermined plane orientation, to a mean value mo of the absolute value of the off angle thereof is 0.005 or more and 0.6 or less. Accordingly, there is provided a low-cost and large-diameter group III nitride composite substrate including a group III nitride film having a large thickness, a small thickness variation, and a high crystal quality.

Abstract: An epitaxial-deposition composite substrate, of more than about 50 mm diameter, in which a nitride-compound semiconductor first substrate is bonded together with a second substrate of either identical or different material. The first substrate is ion-implanted, and on its nitrogen-face side is coated with a special film of thickness within a predetermined range. On a bonding side of the second substrate a special coating of thickness within the predetermined range is formed. The join created by the coated nitrogen-face side of the first substrate being bonded to the coated bonding side of the second substrate occupies at least 90% of the surface area where the two substrates meet.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A composite-substrate manufacturing method is provided with: a step of carrying out implantation of ions through a surface of a bulk substrate composed of the nitride compound semiconductor; a step of setting said surface of the bulk substrate against the second substrate, and bonding the bulk substrate and the second substrate together to obtain a bonded substrate; a step of elevating the temperature of the bonded substrate to a first temperature; a step of sustaining the first temperature for a fixed time; and a step of producing a composite substrate by severing the remaining portion of the bulk substrate from the bonded substrate; characterized in that a predetermined formula as for the first temperature, the thermal expansion coefficient of the first substrate, and the thermal expansion coefficient of the second substrate is satisfied.

Abstract: A method for producing a Group III nitride crystal includes the steps of cutting a plurality of Group III nitride crystal substrates 10p and 10q having a major surface from a Group III nitride bulk crystal 1, the major surfaces 10pm and 10qm having a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20?21}, {20?2?1}, {22?41}, and {22?4?1}, transversely arranging the substrates 10p and 10q adjacent to each other such that the major surfaces 10pm and 10qm of the substrates 10p and 10q are parallel to each other and each [0001] direction of the substrates 10p and 10q coincides with each other, and growing a Group III nitride crystal 20 on the major surfaces 10pm and 10qm of the substrates 10p and 10q.

Abstract: A GaN single crystal substrate has a main surface with an area of not less than 10 cm2, the main surface has a plane orientation inclined by not less than 65° and not more than 85° with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5×10?5, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25° C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.

Abstract: A GaN substrate is stored within an atmosphere in which the oxygen concentration is not greater than 15 vol. % and the water-vapor concentration is not greater than 20 g/m3. The GaN substrate (1) has a planar first principal face (1m), and in an arbitrary point (P) along the first principal face (1m) and separated 3 mm or more from the outer edge thereof, the GaN substrate's plane orientation has an off-inclination angle ?? of ?10° or more, 10° or less with respect to the plane orientation of an arbitrarily designated crystalline plane (1a) that is inclined 50° or more, 90° or less with respect to a plane (1c), being either the (0001) plane or the (000 1) plane, through the arbitrary point. This enables storing GaN substrates whose principal-face plane orientation is other than (0001) or (000 1), making available GaN substrates with which semiconductor devices of favorable properties can be manufactured.