Abstract: A GaAs crystal (35) has ?x(1) not greater than 20 cm?1 in an expression 1 ? ? ? x ? ( 1 ) = ? i = 1 s ? ? X i - X BL ? s Expression ? ? 1 where xi represents a Raman shift of a first peak attributed to oscillation of a longitudinal optical phonon of GaAs in a Raman spectrum measured at an ith point in measurement of Raman spectra at s points in a (100) plane, xBL represents a Raman shift of an emission line peak of neon, and i and s are each a natural number greater than 0.

Abstract: A GaAs crystal (35) has ?x(1) not greater than 20 cm?1 in an expression 1 ? ? ? x ? ( 1 ) = ? i = 1 s ? ? X i - X BL ? s Expression ? ? 1 where xi represents a Raman shift of a first peak attributed to oscillation of a longitudinal optical phonon of GaAs in a Raman spectrum measured at an ith point in measurement of Raman spectra at s points in a (100) plane, xBL represents a Raman shift of an emission line peak of neon, and i and s are each a natural number greater than 0.

Abstract: A GaAs crystal has ?x(1) not greater than 20 cm?1 in an expression 1 ? ? ? x ? ( 1 ) = ? i = 1 s ? ? x i - x BL ? ? s Expression ? ? 1 where xi represents a Raman shift of a first peak attributed to oscillation of a longitudinal optical phonon of GaAs in a Raman spectrum measured at an ith point in measurement of Raman spectra at s points in a (100) plane, xBL represents a Raman shift of an emission line peak of neon, and i and s are each a natural number greater than 0.

Abstract: A GaAs crystal has ?x(1) not greater than 20 cm?1 in an expression 1 ? ? ? x ? ( 1 ) = ? i = 1 s ? ? x i - x BL ? ? s Expression ? ? 1 where xi represents a Raman shift of a first peak attributed to oscillation of a longitudinal optical phonon of GaAs in a Raman spectrum measured at an ith point in measurement of Raman spectra at s points in a (100) plane, xBL represents a Raman shift of an emission line peak of neon, and i and s are each a natural number greater than 0.

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 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: 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 compound semiconductor single-crystal manufacturing device (1) is furnished with: a laser light source (6) making it possible to sublime a source material by directing a laser beam onto the material; a reaction vessel (2) having a laser entry window (5) through which the laser beam output from the laser light source (6) can be transmitted to introduce the beam into the vessel interior, and that is capable of retaining a starting substrate (3) where sublimed source material is recrystallized; and a heater (7) making it possible to heat the starting substrate (3). The laser beam is shone on, to heat and thereby sublime, the source material within the reaction vessel (2), and compound semiconductor single crystal is grown by recrystallizing the sublimed source material onto the starting substrate (3); afterwards the laser beam is employed to separate the compound semiconductor single crystal from the starting substrate (3).

Abstract: III-nitride crystal composites are made up of especially processed crystal slices cut from III-nitride bulk crystal having, ordinarily, a {0001} major surface and disposed adjoining each other sideways, and of III-nitride crystal epitaxially on the bulk-crystal slices. The slices are arranged in such a way that their major surfaces parallel each other, but are not necessarily flush with each other, and so that the [0001] directions in the slices are oriented in the same way.

Abstract: Flat, thin AlN membranes and methods of their manufacture are made available. An AlN thin film (2) contains between 0.001 wt. % and 10 wt. % additive atomic element of one or more type selected from Group-III atoms, Group-IV atoms and Group-V atoms. Onto a base material (1), the AlN thin film (2) is formable utilizing a plasma generated by setting inside a vacuum chamber a sintered AlN ceramic containing between 0.001 wt. % and 10 wt. % additive atomic element of one or more type selected from Group-III atoms, Group-IV atoms and Group-V atoms, and with the base material having been set within the vacuum chamber, irradiating the sintered AlN ceramic with a laser.

Abstract: A method of producing an AlxGa(1-x)N (0<x?1) single crystal of the present invention is directed to growing an AlxGa(1-x)N single crystal by sublimation. The method includes the steps of preparing an underlying substrate, preparing a raw material of high purity, and growing an AlxGa(1-x)N single crystal on the underlying substrate by sublimating the raw material. At the AlxGa(1-x)N single crystal, the refractive index with respect to light at a wavelength greater than or equal to 250 nm and less than or equal to 300 nm is greater than or equal to 2.4, and the refractive index with respect to light at a wavelength greater than 300 nm and less than 350 nm is greater than or equal to 2.3, measured at 300K.

Abstract: III-nitride crystal composites are made up of especially processed crystal slices cut from III-nitride bulk crystal having, ordinarily, a {0001} major surface and disposed adjoining each other sideways, and of III-nitride crystal epitaxially on the bulk-crystal slices. The slices are arranged in such a way that their major surfaces parallel each other, but are not necessarily flush with each other, and so that the [0001] directions in the slices are oriented in the same way.

Abstract: Methods of growing and manufacturing aluminum nitride crystal, and aluminum nitride crystal produced by the methods. Preventing sublimation of the starting substrate allows aluminum nitride crystal of excellent crystallinity to be grown at improved growth rates. The aluminum nitride crystal growth method includes the following steps. Initially, a laminar baseplate is prepared, furnished with a starting substrate having a major surface and a back side, a first layer formed on the back side, and a second layer formed on the first layer. Aluminum nitride crystal is then grown onto the major surface of the starting substrate by vapor deposition. The first layer is made of a substance that at the temperatures at which the aluminum nitride crystal is grown is less liable to sublimate than the starting substrate. The second layer is made of a substance whose thermal conductivity is higher than that of the first layer.

Abstract: A method for growing a Group III nitride semiconductor crystal is provided with the following steps: First, a chamber including a heat-shielding portion for shielding heat radiation from a material 13 therein is prepared. Then, material 13 is arranged on one side of heat-shielding portion in chamber. Then, by heating material to be sublimated, a material gas is deposited on the other side of heat-shielding portion in chamber so that a Group III nitride semiconductor crystal is grown.

Abstract: The present III-nitride crystal manufacturing method, a method of manufacturing a III-nitride crystal (20) having a major surface (20m) of plane orientation other than {0001}, designated by choice, includes: a step of slicing III-nitride bulk crystal (1) into a plurality of III-nitride crystal substrates (10p), (10q) having major surfaces (10pm), (10qm) of the designated plane orientation; a step of disposing the substrates (10p), (10q) adjoining each other sideways in such a way that the major surfaces (10pm), (10qm) of the substrates (10p), (10q) parallel each other and so that the [0001] directions in the substrates (10p), (10q) are oriented in the same way; and a step of growing III-nitride crystal (20) onto the major surfaces (10pm), (10qm) of the substrates (10p), (10q).

Abstract: There is provided an AlGaN bulk crystal manufacturing method for manufacturing a high-quality AlGaN bulk crystal having a large thickness. Also, there is provided an AlGaN substrate manufacturing method for manufacturing a high-quality AlGaN substrate. The AlGaN bulk crystal manufacturing method includes the following steps: First, a support substrate composed of AlaGa(1-a)N (0<a?1) is prepared. Then, a bulk crystal composed of AlbGa(1-b)N (0<b<1) with a primary surface is grown on the support substrate. The composition ratio a of Al in the support substrate is larger than the composition ratio b of Al in the bulk crystal. The AlGaN substrate manufacturing method includes a step of cutting out at least one AlbGa(1-b)N substrate from the bulk crystal.

Abstract: A method of producing an AlxGa(1-x)N (0<x?1) single crystal of the present invention is directed to growing an AlxGa(1-x)N single crystal by sublimation. The method includes the steps of preparing an underlying substrate, preparing a raw material of high purity, and growing an AlxGa(1-x)N single crystal on the underlying substrate by sublimating the raw material. At the AlxGa(1-x)N single crystal, the refractive index with respect to light at a wavelength greater than or equal to 250 nm and less than or equal to 300 nm is greater than or equal to 2.4, and the refractive index with respect to light at a wavelength greater than 300 nm and less than 350 nm is greater than or equal to 2.3, measured at 300K.

Abstract: A method for producing a group III-nitride crystal having a large thickness and high quality and a group III-nitride crystal are provided. A method for producing a group III-nitride crystal 13 includes the following steps: A underlying substrate 11 having a major surface 11a tilted toward the <1-100> direction with respect to the (0001) plane is prepared. The group III-nitride crystal 13 is grown by vapor-phase epitaxy on the major surface 11a of the underlying substrate 11. The major surface 11a of the underlying substrate 11 is preferably a plane tilted at an angle of ?5° to 5° from the {01-10} plane.