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: Si(1-v-w-x)CwAlxNv crystals in a mixed crystal state are formed. A method for manufacturing an easily processable Si(1-v-w-x)CwAlxNv substrate, a method for manufacturing an epitaxial wafer, a Si(1-v-w-x)CwAlxNv substrate, and an epitaxial wafer are provided. A method for manufacturing a Si(1-v-w-x)CwAlxNv substrate 10a includes the following steps. First, a Si substrate 11 is prepared. A Si(1-v-w-x)CwAlxNv layer 12 (0<v<1, 0<w<1, 0<x<1, and 0<v+w+x<1) is then grown on the Si substrate 11 by a pulsed laser deposition method.

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: A composite base of the present invention includes a sintered base and a base surface flattening layer disposed on the sintered base, and the base surface flattening layer has a surface RMS roughness of not more than 1.0 nm. A composite substrate of the present invention includes the composite base and a semiconductor crystal layer disposed on a side of the composite base where the base surface flattening layer is located, and a difference between a thermal expansion coefficient of the sintered base and a thermal expansion coefficient of the semiconductor crystal layer is not more than 4.5×10?6K?1. Thereby, a composite substrate in which a semiconductor crystal layer is attached to a sintered base, and a composite base suitably used for that composite substrate are provided.

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 wavelength conversion element having an improved property-maintaining life and a method for manufacturing the wavelength conversion element are provided. A wavelength conversion element 10a has an optical waveguide 13. The wavelength of incoming light 101 input from one end 13a of the optical waveguide 13 is converted and outgoing light 102 is output from the other end 13b of the optical waveguide 13. The wavelength conversion element includes a first crystal 11 composed of AlxGa(1-x)N (0.5?x?1); and a second crystal 12 having the same composition as that of the first crystal. The first and second crystals 11 and 12 form a domain-inverted structure in which a polarization direction is periodically reversed along the optical waveguide 13, and the domain-inverted structure satisfies quasi phase matching conditions with respect to the incoming light 101. At least one of the first and second crystals has a dislocation density of 1×103 cm?2 or more and less than 1×107 cm?2.

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 1.0 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 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 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: Nitride semiconductor crystal manufacturing method according to which the following steps are carried out. To begin with, a crucible (101) for interiorly carrying source material (17) is prepared. Within the crucible (101), heating of the source material (17) sublimes the source material, and by the condensing of source-material gases caused, nitride semiconductor crystal is grown. In the preparation step, a crucible (101) made from a metal whose melting point is higher than that of the source material (17) is prepared.

Abstract: Affords a wavelength converter manufacturing method and a wavelength converter whereby the transmissivity can be improved. A method of manufacturing a wavelength converter (10a) is provided with the following steps. At first, crystal is grown. Then a first crystal (11) and a second crystal (12) are formed by sectioning the crystal into two or more in such a way that the domains are the reverse of each other. The first and second crystals (11) and (12) are then interlocked in such a way that a domain inversion structure in which the polar directions of the first and second crystals (11) and (12) periodically reverse along an optical waveguide (13) is formed, and the domain inversion structure satisfies quasi-phase-matching conditions for an incoming beam (101).

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 wavelength conversion element having an improved property-maintaining life and a method for manufacturing the wavelength conversion element are provided. A wavelength conversion element 10a has an optical waveguide 13. The wavelength of incoming light 101 input from one end 13a of the optical waveguide 13 is converted and outgoing light 102 is output from the other end 13b of the optical waveguide 13. The wavelength conversion element includes a first crystal 11 composed of AlxGa(1-x)N (0.5?x?1); and a second crystal 12 having the same composition as that of the first crystal. The first and second crystals 11 and 12 form a domain-inverted structure in which a polarization direction is periodically reversed along the optical waveguide 13, and the domain-inverted structure satisfies quasi phase matching conditions with respect to the incoming light 101. At least one of the first and second crystals has a dislocation density of 1×103 cm?2 or more and less than 1×107 cm?2.

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.