Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate (10) including a support substrate (11) dissoluble in hydrofluoric acid and a single crystal film (13) arranged on a side of a main surface (11m) of the support substrate (11), a coefficient of thermal expansion in the main surface (11m) of the support substrate (11) being more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal, forming a GaN-based film (20) on a main surface (13m) of the single crystal film (13) arranged on the side of the main surface (11m) of the support substrate (11), and removing the support substrate (11) by dissolving the support substrate (11) in hydrofluoric acid. Thus, the method of manufacturing a GaN-based film capable of efficiently obtaining a GaN-based film having a large main surface area, less warpage, and good crystallinity, as well as a composite substrate used therefor are provided.

Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate including a support substrate dissoluble in hydrofluoric acid and a single crystal film arranged on a side of a main surface of the support substrate, a coefficient of thermal expansion in the main surface of the support substrate being more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal, forming a GaN-based film on a main surface of the single crystal film arranged on the side of the main surface of the support substrate, and removing the support substrate by dissolving the support substrate in hydrofluoric acid. Thus, the method of manufacturing a GaN-based film capable of efficiently obtaining a GaN-based film having a large main surface area, less warpage, and good crystallinity, as well as a composite substrate used therefor are provided.

Abstract: A method of manufacturing a nitride substrate includes the following steps. Firstly, a nitride crystal is grown. Then, the nitride substrate including a front surface is cut from the nitride crystal. In the step of cutting, the nitride substrate is cut such that an off angle formed between an axis orthogonal to the front surface and an m-axis or an a-axis is greater than zero. When the nitride crystal is grown in a c-axis direction, in the step of cutting, the nitride substrate is cut from the nitride crystal along a flat plane which passes through a front surface and a rear surface of the nitride crystal and does not pass through a line segment connecting a center of a radius of curvature of the front surface with a center of a radius of curvature of the rear surface of the nitride crystal.

Abstract: A method of manufacturing a nitride substrate includes the following steps. Firstly, a nitride crystal is grown. Then, the nitride substrate including a front surface is cut from the nitride crystal. In the step of cutting, the nitride substrate is cut such that an off angle formed between an axis orthogonal to the front surface and an m-axis or an a-axis is greater than zero. When the nitride crystal is grown in a c-axis direction, in the step of cutting, the nitride substrate is cut from the nitride crystal along a flat plane which passes through a front surface and a rear surface of the nitride crystal and does not pass through a line segment connecting a center of a radius of curvature of the front surface with a center of a radius of curvature of the rear surface of the nitride crystal.

Abstract: A method of manufacturing a semiconductor wafer of the present invention includes the steps of: obtaining a composite base by forming a base surface flattening layer having a surface RMS roughness of not more than 1.0 nm on a base; obtaining a composite substrate by attaching a semiconductor crystal layer to a side of the composite base where the base surface flattening layer is located; growing at least one semiconductor layer on the semiconductor crystal layer of the composite substrate; and obtaining the semiconductor wafer including the semiconductor crystal layer and the semiconductor layer by removing the base surface flattening layer by wet etching and thereby separating the semiconductor crystal layer from the base.

Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate, the composite substrate including a support substrate in which a coefficient of thermal expansion in a main surface is more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal in a direction of a axis and a single crystal film arranged on a side of the main surface of the support substrate, the single crystal film having threefold symmetry with respect to an axis perpendicular to a main surface of the single crystal film, and forming a GaN-based film on the main surface of the single crystal film in the composite substrate. Thus, a method of manufacturing a GaN-based film capable of manufacturing a GaN-based film having a large main surface area and less warpage is provided.

Abstract: A method of manufacturing a GaN-based film includes the steps of preparing a composite substrate, the composite substrate including a support substrate in which a coefficient of thermal expansion in its main surface is more than 0.8 time and less than 1.0 time as high as a coefficient of thermal expansion of GaN crystal in a direction of a axis and a single crystal film arranged on a main surface side of the support substrate, the single crystal film having threefold symmetry with respect to an axis perpendicular to a main surface of the single crystal film, and forming a GaN-based film on the main surface of the single crystal film in the composite substrate, the single crystal film in the composite substrate being an SiC film. Thus, a method of manufacturing a GaN-based film capable of manufacturing a GaN-based film having a large main surface area and less warpage without crack being produced in a substrate is provided.

Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate, the composite substrate including a support substrate in which a coefficient of thermal expansion in a main surface is more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal in a direction of a axis and a single crystal film arranged on a side of the main surface of the support substrate, the single crystal film having threefold symmetry with respect to an axis perpendicular to a main surface of the single crystal film, and forming a GaN-based film on the main surface of the single crystal film in the composite substrate. Thus, a method of manufacturing a GaN-based film capable of manufacturing a GaN-based film having a large main surface area and less warpage is provided.

Abstract: A method of manufacturing a GaN-based film includes the steps of preparing a composite substrate, the composite substrate including a support substrate in which a coefficient of thermal expansion in its main surface is more than 0.8 time and less than 1.0 time as high as a coefficient of thermal expansion of GaN crystal in a direction of a axis and a single crystal film arranged on a main surface side of the support substrate, the single crystal film having threefold symmetry with respect to an axis perpendicular to a main surface of the single crystal film, and forming a GaN-based film on the main surface of the single crystal film in the composite substrate, the single crystal film in the composite substrate being an SiC film. Thus, a method of manufacturing a GaN-based film capable of manufacturing a GaN-based film having a large main surface area and less warpage without crack being produced in a substrate is provided.

Abstract: A III-nitride semiconductor electronic device comprises a semiconductor laminate provided on a primary surface of a substrate, a first electrode in contact with the semiconductor laminate, and a second electrode. The semiconductor laminate includes a channel layer and a barrier layer making a junction with the channel layer. The channel layer comprises first III-nitride semiconductor containing aluminum as a Group III constituent element, and the barrier layer comprises second III-nitride semiconductor containing aluminum as a Group III constituent element. The semiconductor laminate including first, second and third regions arranged along the primary surface, and the third region is located between the first region and the second region. The barrier layer includes first to third portions included in the first to third regions, respectively.

Abstract: Affords nitride semiconductor crystal manufacturing apparatuses that are durable and that are for manufacturing nitride semiconductor crystal in which the immixing of impurities from outside the crucible is kept under control, and makes methods for manufacturing such nitride semiconductor crystal, and the nitride semiconductor crystal itself, available. A nitride semiconductor crystal manufacturing apparatus (100) is furnished with a crucible (101), a heating unit (125), and a covering component (110). The crucible (101) is where, interiorly, source material (17) is disposed. The heating unit (125) is disposed about the outer periphery of the crucible (101), where it heats the crucible (101) interior. The covering component (110) is arranged in between the crucible (101) and the heating unit (125).

Abstract: A method of manufacturing a semiconductor wafer of the present invention includes the steps of: obtaining a composite base by forming a base surface flattening layer having a surface RMS roughness of not more than 1.0 nm on a base; obtaining a composite substrate by attaching a semiconductor crystal layer to a side of the composite base where the base surface flattening layer is located; growing at least one semiconductor layer on the semiconductor crystal layer of the composite substrate; and obtaining the semiconductor wafer including the semiconductor crystal layer and the semiconductor layer by removing the base surface flattening layer by wet etching and thereby separating the semiconductor crystal layer from the base.

Abstract: A protective-film-attached composite substrate includes a support substrate, an oxide film disposed on the support substrate, a semiconductor layer disposed on the oxide film, and a protective film protecting the oxide film by covering a portion that is a part of the oxide film and covered with none of the support substrate and the semiconductor layer. A method of manufacturing a semiconductor device includes the steps of: preparing the protective-film-attached composite substrate; and epitaxially growing, on the semiconductor layer of the protective-film-attached composite substrate, at least one functional semiconductor layer causing an essential function of a semiconductor device to be performed. Thus, there are provided a protective-film-attached composite substrate having a large effective region where a high-quality functional semiconductor layer can be epitaxially grown, and a method of manufacturing a semiconductor device in which the protective-film-attached composite substrate is used.

Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate including a support substrate dissoluble in hydrofluoric acid and a single crystal film arranged on a side of a main surface of the support substrate, a coefficient of thermal expansion in the main surface of the support substrate being more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal, forming a GaN-based film on a main surface of the single crystal film arranged on the side of the main surface of the support substrate, and removing the support substrate by dissolving the support substrate in hydrofluoric acid. Thus, the method of manufacturing a GaN-based film capable of efficiently obtaining a GaN-based film having a large main surface area, less warpage, and good crystallinity, as well as a composite substrate used therefor are provided.

Abstract: The present method of manufacturing a GaN-based film includes the steps of preparing a composite substrate, the composite substrate including a support substrate in which a coefficient of thermal expansion in a main surface is more than 0.8 time and less than 1.2 times as high as a coefficient of thermal expansion of GaN crystal in a direction of a axis and a single crystal film arranged on a side of the main surface of the support substrate, the single crystal film having threefold symmetry with respect to an axis perpendicular to a main surface of the single crystal film, and forming a GaN-based film on the main surface of the single crystal film in the composite substrate. Thus, a method of manufacturing a GaN-based film capable of manufacturing a GaN-based film having a large main surface area and less warpage is provided.

Abstract: A group III nitride composite substrate includes a support substrate, an oxide film formed on the support substrate, and a group III nitride layer formed on the oxide film. The oxide film may be a film selected from the group consisting of a TiO2 film and a SrTiO3 film, and an impurity may be added to the oxide film. Accordingly, the group III nitride composite substrate having a high bonding strength between the support substrate and the group III nitride layer is provided.

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: 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: Affords a GaN single-crystal mass, a method of its manufacture, and a semiconductor device and method of its manufacture, whereby when the GaN single-crystal mass is being grown, and when the grown GaN single-crystal mass is being processed into a substrate or like form, as well as when an at least single-lamina semiconductor layer is being formed onto a single-crystal GaN mass in substrate form to manufacture semiconductor devices, cracking is controlled to a minimum. The GaN single-crystal mass 10 has a wurtzitic crystalline structure and, at 30° C., its elastic constant C11 is from 348 GPa to 365 GPa and its elastic constant C13 is from 90 GPa to 98 GPa; alternatively its elastic constant C11 is from 352 GPa to 362 GPa.