Abstract: A GaN-crystal free-standing substrate obtained from a GaN crystal grown by HVPE with a (0001) plane serving as a crystal growth plane and at least one plane of a {10-11} plane and a {11-22} plane serving as a crystal growth plane that constitutes a facet crystal region, except for the side surface of the crystal, wherein the (0001)-plane-growth crystal region has a carbon concentration of 5×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or more and 2×1018 atoms/cm3 or less, and an oxygen concentration of 1×1017 atoms/cm3 or less; and the facet crystal region has a carbon concentration of 3×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or less, and an oxygen concentration of 5×1017 atoms/cm3 or more and 5×1018 atoms/cm3 or less.

Abstract: The invention relates to a GaN-crystal free-standing substrate obtained from a GaN crystal grown by HVPE with a (0001) plane serving as a crystal growth plane and at least one plane of a {10-11} plane and a {11-22} plane serving as a crystal growth plane that constitutes a facet crystal region, except for the side surface of the crystal, wherein the (0001)-plane-growth crystal region has a carbon concentration of 5×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or more and 2×1018 atoms/cm3 or less, and an oxygen concentration of 1×1017 atoms/cm3 or less; and the facet crystal region has a carbon concentration of 3×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or less, and an oxygen concentration of 5×1017 atoms/cm3 or more and 5×1018 atoms/cm3 or less.

Abstract: A method for manufacturing silicon carbide single crystal having a diameter larger than 100 mm by sublimation includes the following steps. A seed substrate made of silicon carbide and silicon carbide raw material are prepared. Silicon carbide single crystal is grown on the growth face of the seed substrate by sublimating the silicon carbide raw material. In the step of growing silicon carbide single crystal, the maximum growing rate of the silicon carbide single crystal growing on the growth face of the seed substrate is greater than the maximum growing rate of the silicon carbide crystal growing on the surface of the silicon carbide raw material. Thus, there can be provided a method for manufacturing silicon carbide single crystal allowing a thick silicon carbide single crystal film to be obtained, when silicon carbide single crystal having a diameter larger than 100 mm is grown.

Abstract: Toward making available III nitride crystal substrates advantageously employed in light-emitting devices, and light-emitting devices incorporating the substrates and methods of manufacturing the light-emitting devices, a III nitride crystal substrate has a major face whose surface area is not less than 10 cm2 and, in a major-face principal region excluding the peripheral margin of the major face from its outer periphery to a 5 mm separation from its outer periphery, the total dislocation density is from 1×104 cm?2 to 3×106 cm?2, and the ratio of screw-dislocation density to the total dislocation density is 0.5 or greater.

Abstract: There are provided a method for manufacturing a Si(1-v-w-x)CwAlxNv substrate having a reduced number of cracks and high processability, a method for manufacturing an epitaxial wafer, a Si(1-v-w-x)CwAlxNv substrate, and an epitaxial wafer. 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 (0<v<1, 0<w<1, 0<x<1, and 0<v+w+x<1) is then grown on the Si substrate at a temperature below 550° C.

Abstract: A method for manufacturing a silicon carbide single-crystal having a diameter of more than 100 mm and a maximum height of 20 mm or more using a sublimation method includes the following steps. That is, there are prepared a seed substrate made of silicon carbide and a silicon carbide source material. By sublimating the silicon carbide source material, the silicon carbide single-crystal is grown on a growth surface of the seed substrate. In the step of growing the silicon carbide single-crystal, a first carbon member provided at a position facing a side wall of the seed substrate is etched at a rate of 0.1 mm/hour or less. By suppressing a change in growth condition for the silicon carbide single-crystal in the crucible, there can be provided a method for manufacturing a silicon carbide single-crystal so as to stably grow the silicon carbide single-crystal.

Abstract: A method for producing a group III nitride crystal in the present invention includes the steps of cutting a plurality of group III nitride crystal substrates 10p and 10q having a main plane from a group III nitride bulk crystal 1, the main planes 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 main planes 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 main planes 10pm and 10qm of the substrates 10p and 10q.

Abstract: Freestanding III-nitride single-crystal substrates whose average dislocation density is not greater than 5×105 cm?2 and that are fracture resistant, and a method of manufacturing semiconductor devices utilizing such freestanding III-nitride single-crystal substrates are made available. The freestanding III-nitride single-crystal substrate includes one or more high-dislocation-density regions (20h), and a plurality of low-dislocation-density regions (20k) in which the dislocation density is lower than that of the high-dislocation-density regions (20h), wherein the average dislocation density is not greater than 5×105 cm?2. Herein, the ratio of the dislocation density of the high-dislocation-density region(s) (20h) to the average dislocation density is sufficiently large to check the propagation of cracks in the substrate. And the semiconductor device manufacturing method utilizes the freestanding III-nitride single crystal substrate (20p).

Abstract: Method of high-yield manufacturing superior semiconductor devices includes: a step of preparing a GaN substrate having a ratio St/S—of collective area (St cm2) of inversion domains in, to total area (S cm2) of the principal face of, the GaN substrate—of no more than 0.5, with the density along the (0001) Ga face, being the substrate principal face, of inversion domains whose surface area where the polarity in the [0001] direction is inverted with respect to the principal domain (matrix) is 1 ?m2 or more being D cm?2; and a step of growing on the GaN substrate principal face an at least single-lamina semiconductor layer to form semiconductor devices in which the product Sc×D of the area Sc of the device principal faces, and the density D of the inversion domains is made less than 2.3.

Abstract: Affords large-diametric-span AlN crystals, applicable to various types of semiconductor devices, with superior crystallinity, a method of growing the AlN crystals, and AlN crystal substrates. The AlN crystal growth method is a method in which an AlN crystal (4) is grown by vapor-phase epitaxy onto a seed crystal substrate (2) placed inside a crystal-growth compartment (24) within a crystal-growth vessel (12) provided within a reaction chamber, and is characterized in that during growth of the crystal, carbon-containing gas is supplied to the inside of the crystal-growth compartment (24).

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: At least one single crystal substrate, each having a backside surface and made of silicon carbide, and a supporting portion having a main surface and made of silicon carbide, are prepared. In this preparing step, at least one of the backside surface and main surface is formed by machining. By this forming step, a surface layer having distortion in the crystal structure is formed on at least one of the backside surface and main surface. The surface layer is removed at least partially. Following this removing step, the backside surface and main surface are connected to each other.

Abstract: Provided is a method for fabricating a wafer product including an active layer grown on a gallium oxide substrate and allowing an improvement in emission intensity. In step S105, a buffer layer 13 comprised of a Group III nitride such as GaN, AlGaN, or AlN is grown at 600 Celsius degrees on a primary surface 11a of a gallium oxide substrate 11. After the growth of the buffer layer 13, while supplying a gas G2, which contains hydrogen and nitrogen, into a growth reactor 10, the gallium oxide substrate 11 and the buffer layer 13 are exposed to an atmosphere in the growth reactor 11 at 1050 Celsius degrees. A Group III nitride semiconductor layer 15 is grown on the modified buffer layer. The modified buffer layer includes, for example, voids. The Group III nitride semiconductor layer 15 can be comprised of GaN and AlGaN. When the Group III nitride semiconductor layer 15 is formed of these materials, excellent crystal quality is obtained on the modified buffer layer 14.

Abstract: A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm?2, a threading screw dislocation density of not more than 1×104 cm?2, a threading edge dislocation density of not more than 1×104 cm?2, a basal plane dislocation density of not more than 1×104 cm?2, a stacking fault density of not more than 0.1 cm?1, a conductive impurity concentration of not less than 1×1018 cm?2, a residual impurity concentration of not more than 1×1016 cm?2, and a secondary phase inclusion density of not more than 1 cm?3.

Abstract: Provided is a method for manufacturing a silicon carbide crystal, including the steps of: placing a seed substrate and a source material for the silicon carbide crystal within a growth container; and growing the silicon carbide crystal with a diameter of more than 4 inches on a surface of the seed substrate by a sublimation method, in the step of growing, a pressure within the growth container being changed from a predetermined pressure, at a predetermined change rate.

Abstract: An edge region has a width of 5 mm. A valid region is surrounded by the edge region, and has an area greater than or equal to 100 cm2. At the valid region, a micropipe having a cross-sectional area exceeding 1 ?m2 is not present. The valid region includes a plurality of high-quality regions occupying 70% or more of the valid region. Each of the plurality of high-quality regions has a square shape, an area greater than or equal to 1 cm2, and a micropipe density less than or equal to 1 micropipe per 1 cm2.

Abstract: Affords methods of growing III nitride single crystals of favorable crystallinity with excellent reproducibility, and the III nitride crystals obtained by the growth methods. One method grows a III nitride single crystal (3) inside a crystal-growth vessel (11), the method being characterized in that a porous body formed from a metal carbide, whose porosity is between 0.1% and 70% is employed in at least a portion of the crystal-growth vessel (11). Employing the crystal-growth vessel (11) makes it possible to discharge from 1% to 50% of a source gas (4) inside the crystal-growth vessel (11) via the pores in the porous body to the outside of the crystal-growth vessel (11).

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: Silicon carbide single crystal is prepared. Using the silicon carbide single crystal as a material, a silicon carbide substrate having a first face and a second face located at a side opposite to the first face is formed. In the formation of the silicon carbide substrate, a first processed damage layer and a second processed damage layer are formed at the first face and second face, respectively. The first face is polished such that at least a portion of the first processed damage layer is removed and the surface roughness of the first face becomes less than or equal to 5 nm. At least a portion of the second processed damage layer is removed while maintaining the surface roughness of the second plane greater than or equal to 10 nm.

Abstract: This III-nitride single-crystal growth method, being a method of growing a AlxGa1-xN single crystal (4) by sublimation, is furnished with a step of placing source material (1) in a crucible (12), and a step of sublimating the source material (1) to grow AlxGa1-xN (0<x?1) single crystal (4) in the crucible (12), with the AlyGa1-yN (0<y?1) source (2) and an impurity element (3), which is at least one selected from the group consisting of IVb elements and IIa elements, being included in the source material (1). This growth method makes it possible to stably grow bulk III-nitride single crystals of low dislocation density and of favorable crystallinity.