Abstract: A refrigeration cycle device includes a heat pump cycle, a high-temperature heat medium circuit, and a low-temperature heat medium circuit. The low-temperature heat medium circuit includes a plurality of heat absorption devices configured to have a heat absorption amount to be absorbed by the low-temperature heat medium flowing out of a low-temperature heat medium-refrigerant heat exchanger, and a heat absorption adjusting unit configured to change the heat absorption amount of the low-temperature heat medium in the respective heat absorption devices.

Abstract: A driving assistance device includes a memory and a processor. The processor acquires travel information including acceleration of a moving body. The processor presents, to the moving body, information regarding cargo collapse on the moving body that is specified on the basis of a distribution of the acceleration of the moving body in multiple axes on the basis of the travel information.

Abstract: Assuming that r (m) represents the radius of a GaN substrate, t1 (m) represents the thickness of the GaN substrate, h1 (m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t2 (m) represents the thickness of an AlxGa(1-X)N layer, h2 (m) represents a warp of the epitaxialwafer, a1 represents the lattice constant of GaN and a2 represents the lattice constant of AlN, the value t1 found by the following expression is decided as the minimum thickness (t1) of the GaN substrate: (1.5×1011×t13+1.2×1011×t23)×{1/(1.5×1011×t1)+1/(1.2×1011×t2)}/{15.96×x×(1?a2/a1)}×(t1+t2)+(t1×t2)/{5.32×x×(1?a2/a1)}?(r2+h2)/2h=0 A GaN substrate having a thickness of at least this minimum thickness (t1) and less than 400 ?m is formed.

Abstract: There is provided a method of producing a thin GaN film-joined substrate, including the steps of: joining on a GaN bulk crystalline body a substrate different in type or chemical composition from GaN; and dividing the GaN bulk crystalline body at a plane having a distance of at least 0.1 ?m and at most 100 ?m from an interface thereof with the substrate different in type, to provide a thin film of GaN on the substrate different in type, wherein the GaN bulk crystalline body had a surface joined to the substrate different in type, that has a maximum surface roughness Rmax of at most 20 ?m. Thus a GaN-based semiconductor device including a thin GaN film-joined substrate including a substrate different in type and a thin film of GaN joined firmly on the substrate different in type, and at least one GaN-based semiconductor layer deposited on the thin film of GaN, can be fabricated at low cost.

Abstract: Assuming that r (m) represents the radius of a GaN substrate, t1 (m) represents the thickness of the GaN substrate, h1 (m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t2 (m) represents the thickness of an AlxGa(1-X)N layer, h2 (m) represents a warp of the epitaxialwafer, a1 represents the lattice constant of GaN and a2 represents the lattice constant of AlN, the value t1 found by the following expression is decided as the minimum thickness (t1) of the GaN substrate: (1.5×1011×t13+1.2×1011×t23)×{1/(1.5×1011×t1)+1/(1.2×1011×t2)}/{15.96×x×(1?a2/a1)}×(t1+t2)+(t1×t2)/{5.32×x×(1?a2/a1)}?(r2+h2)/2h=0 A GaN substrate having a thickness of at least this minimum thickness (t1) and less than 400 ?m is formed.

Abstract: Assuming that r (m) represents the radius of a GaN substrate, t1 (m) represents the thickness of the GaN substrate, h1 (m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t2 (m) represents the thickness of an AlxGa(1-x)N layer, h2 (m) represents a warp of the epitaxialwafer, a1 represents the lattice constant of GaN and a2 represents the lattice constant of AlN, the value t1 found by the following expression is decided as the minimum thickness (t1) of the GaN substrate: (1.5×1011×t13+1.2×1011×t23)×{1/(1.5×1011×t1)+1/(1.2×1011×t2)}/{15.96×x×(1?a2/a1)}×(t1+t2)+(t1×t2)/{5.32×x×(1?a2/a1)}?(r2+h2)/2h=0 A GaN substrate having a thickness of at least this minimum thickness (t1) and less than 400 ?m is formed.

Abstract: There is disclosed a method for forming a gallium nitride layer of which resistivity is 1×106 ?·cm or more, including steps of: forming a gallium nitride layer containing iron on a substrate; and heating said gallium nitride layer formed on said substrate.

Abstract: For a semiconductor laser, a stacked member comprising an active layer is formed on the surface of a GaN single-crystal substrate, a defect aggregation portion is formed on the rear face of the GaN single-crystal substrate, and an electrode is formed so as to be electrically connected to the defect aggregation portion on the rear face. The defect aggregation portion of this semiconductor laser has numerous crystal defects, and so the carrier concentration is high, and the electrical resistivity is lowered significantly. For this reason, in a semiconductor laser of this invention in which an electrode is formed on this defect aggregation portion, an Ohmic contact can easily be obtained between the GaN single-crystal substrate and the electrode, and by this means a lowered driving voltage is realized.

Abstract: A method of forming an iron-doped gallium nitride for a semi-insulating GaN substrate is provided. A substrate (1), such as a (0001)-cut sapphire substrate, is placed on a susceptor of a metalorganic hydrogen chloride vapor phase apparatus (11). Next, gaseous iron compound GFe from a source (13) for an iron compound, such as ferrocene, and hydrogen chloride gas G1HCl from a hydrogen chloride source (15) are caused to react with each other in a mixing container (16) to generate gas GFeComp of an iron-containing reaction product, such as iron chloride (FeCl2). In association with the generation, the iron-containing reaction product GFeComp, first substance gas GN containing elemental nitrogen from a nitrogen source (17), and second substance gas GGa containing elemental gallium are supplied to a reaction tube (21) to form iron-doped gallium nitride (23) on the substrate (1).

Abstract: A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

Abstract: There is provided a method of producing a thin GaN film-joined substrate, including the steps of: joining on a GaN bulk crystalline body a substrate different in type or chemical composition from GaN; and dividing the GaN bulk crystalline body at a plane having a distance of at least 0.1 ?m and at most 100 ?m from an interface thereof with the substrate different in type, to provide a thin film of GaN on the substrate different in type, wherein the GaN bulk crystalline body had a surface joined to the substrate different in type, that has a maximum surface roughness Rmax of at most 20 ?m. Thus a GaN-based semiconductor device including a thin GaN film-joined substrate including a substrate different in type and a thin film of GaN joined firmly on the substrate different in type, and at least one GaN-based semiconductor layer deposited on the thin film of GaN, can be fabricated at low cost.

Abstract: There is provided a method of producing a thin GaN film-joined substrate, including the steps of: joining on a GaN bulk crystalline body a substrate different in type or chemical composition from GaN; and dividing the GaN bulk crystalline body at a plane having a distance of at least 0.1 ?m and at most 100 ?m from an interface thereof with the substrate different in type, to provide a thin film of GaN on the substrate different in type, wherein the GaN bulk crystalline body had a surface joined to the substrate different in type, that has a maximum surface roughness Rmax of at most 20 ?m. Thus a GaN-based semiconductor device including a thin GaN film-joined substrate including a substrate different in type and a thin film of GaN joined firmly on the substrate different in type, and at least one GaN-based semiconductor layer deposited on the thin film of GaN, can be fabricated at low cost.

Abstract: A method of forming an iron-doped gallium nitride for a semi-insulating GaN substrate is provided. A substrate 1, such as a sapphire substrate having the (0001) plane, is placed on a susceptor of a metalorganic hydrogen chloride vapor phase apparatus 11. Next, gaseous iron compound GFe from a source 13 for an iron compound, such as ferrocene, and hydrogen chloride gas G1HCl from a hydrogen chloride source 15 are caused to react with each other in a mixing container 16 to generate gas GFeComp of an iron-containing reaction product, such as iron chloride (FeCl2). In association with the generation, the iron-containing reaction product GFeComp, first substance gas GN containing elemental nitrogen from a nitrogen source 17, and second substance gas GGa containing elemental gallium are supplied to a reaction tube 21 to form iron-doped gallium nitride 23 on the substrate 1.

Abstract: Assuming that r (m) represents the radius of a GaN substrate, t1 (m) represents the thickness of the GaN substrate, h1 (m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t2 (m) represents the thickness of an AlxGa(1?x)N layer, h2 (m) represents a warp of the epitaxialwafer, a1 represents the lattice constant of GaN and a2 represents the lattice constant of AlN, the value t1 found by the following expression is decided as the minimum thickness (t1) of the GaN substrate: (1.5×1011×t13+1.2×1011×t23)×{1/(1.5×1011×t1)+1/(1.2×1011×t2)}/{15.96×x×(1?a2/a1)}×(t1+t2)+(t1×t2)/{5.32×x×(1?a2/a)}?(r2+h2)/2h=0 A GaN substrate having a thickness of at least this minimum thickness (t1) and less than 400 ?m is formed.

Abstract: A method of forming an iron-doped gallium nitride for a semi-insulating GaN substrate is provided. A substrate (1), such as a (0001)-cut sapphire substrate, is placed on a susceptor of a metalorganic hydrogen chloride vapor phase apparatus (11). Next, gaseous iron compound GFe from a source (13) for an iron compound, such as ferrocene, and hydrogen chloride gas G1HCl from a hydrogen chloride source (15) are caused to react with each other in a mixing container (16) to generate gas GFeComp of an iron-containing reaction product, such as iron chloride (FeCl2). In association with the generation, the iron-containing reaction product GFeComp, first substance gas GN containing elemental nitrogen from a nitrogen source (17), and second substance gas GGa containing elemental gallium are supplied to a reaction tube (21) to form iron-doped gallium nitride (23) on the substrate (1).

Abstract: Affords a GaN substrate from which enhanced-emission-efficiency light-emitting and like semiconductor devices can be produced, an epi-substrate in which an epitaxial layer has been formed on the GaN substrate principal surface, a semiconductor device, and a method of manufacturing the GaN substrate. The GaN substrate is a substrate having a principal surface with respect to whose normal vector the [0001] plane orientation is inclined in two different off-axis directions.

Abstract: There is disclosed a method for forming a gallium nitride layer of which resistivity is 1×106?·cm or more, including steps of: forming a gallium nitride layer containing iron on a substrate; and heating said gallium nitride layer formed on said substrate.

Abstract: A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

Abstract: In a semiconductor laser manufacturing method, a GaN single-crystal substrate is formed by slicing a GaN bulk crystal, grown on a c-plane, parallel to an a-plane which is perpendicular to the c-plane. In this substrate, crystal defects extending parallel to the c-axis direction do not readily exert an influence, and degradation of element characteristics due to crystal defects can be suppressed. Further, because the a-plane is a nonpolar plane, improved light emission efficiency and longer wavelengths can be achieved compared with the c-plane, which is a polar plane. Hence a semiconductor laser manufacturing method of this invention enables further improvement of the element characteristics of the semiconductor laser to be fabricated.

Abstract: For a semiconductor laser, a stacked member comprising an active layer is formed on the surface of a GaN single-crystal substrate, a defect aggregation portion is formed on the rear face of the GaN single-crystal substrate, and an electrode is formed so as to be electrically connected to the defect aggregation portion on the rear face. The defect aggregation portion of this semiconductor laser has numerous crystal defects, and so the carrier concentration is high, and the electrical resistivity is lowered significantly. For this reason, in a semiconductor laser of this invention in which an electrode is formed on this defect aggregation portion, an Ohmic contact can easily be obtained between the GaN single-crystal substrate and the electrode, and by this means a lowered driving voltage is realized.