Abstract: A random number generating device of the present disclosure includes: an arithmetic random number generator that generates an arithmetic random number sequence; an arithmetic random number converter that sequentially reads at least one arithmetic random number from the arithmetic random number sequence and converts a value of the read arithmetic random number into a voltage or current value of at least two predetermined levels of gray scale having an identical polarity; a hysteresis unit that outputs values depending on a presently-input voltage or current value and a previously-input voltage or current value with respect to the sequentially-input voltage or current value; and a threshold processor that binarizes the output of the hysteresis unit.

Abstract: A random number generating device of the present disclosure includes: an arithmetic random number generator that generates an arithmetic random number sequence; an arithmetic random number converter that sequentially reads at least one arithmetic random number from the arithmetic random number sequence and converts a value of the read arithmetic random number into a voltage or current value of at least two predetermined levels of gray scale having an identical polarity; a hysteresis unit that outputs values depending on a presently-input voltage or current value and a previously-input voltage or current value with respect to the sequentially-input voltage or current value; and a threshold processor that binarizes the output of the hysteresis unit.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: After a Group III-V compound semiconductor layer, to which a p-type dopant has been introduced, has been formed over a substrate, the compound semiconductor layer is annealed. In the stage of heating the compound semiconductor layer, atoms, deactivating the p-type dopant, are eliminated from the compound semiconductor layer by creating a temperature gradient in the compound semiconductor layer.

Abstract: A semiconductor light-emitting device of Group III-V compound semiconductors includes a quantum well layer, which is formed over a substrate and includes a barrier layer and a well layer that are alternately stacked one upon the other. The band gap of the well layer is narrower than that of the barrier layer. The well layer contains indium and nitrogen, while the barrier layer contains aluminum and nitrogen. In this structure, a tensile strain is induced in the barrier layer, and therefore, a compressive strain induced in the quantum well layer can be reduced. As a result, a critical thickness, at which pits are created, can be increased.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0?u, v, w?1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0?x, y, z?1 and x+y+z=1, by using, as a seed crystal, C planes corresponding to top faces of the convexes exposed from the mask film.

Abstract: A facet-forming layer made of nitride semiconductor containing at least aluminum is formed on a substrate made of gallium nitride (GaN). A facet surface inclined with respect to a C-surface is formed on the surface of the facet-forming layer, and a selective growth layer laterally grows from the inclined facet surface. As a result, the selective growth layer can substantially lattice-match an n-type cladding layer made of n-type AlGaN and grown on the selective growth layer. For example, a laser structure without cracks being generated can be obtained by crystal growth.

Abstract: The method for fabricating a semiconductor includes the steps of: (1) growing a first semiconductor layer made of AlxGa1−xN (0≦x≦1) on a substrate at a temperature higher than room temperature; and (2) growing a second semiconductor layer made of AluGavInwN (0<u≦1, 0≦v≦1, 0≦w≦1, u+v+w=1) over the first semiconductor layer. In the step (1), the mole fraction x of Al of the first semiconductor layer is set so that the lattice constant of the first semiconductor layer at room temperature substantially matches with the lattice constant of the second semiconductor layer in the bulk state after thermal shrinkage or thermal expansion.

Abstract: A method for fabricating a nitride semiconductor device comprising steps of forming a low-temperature deposited layer composed of a Group III-Group V nitride semiconductor containing at least Al onto a surface of substrate (101) at a first temperature; subjecting the low-temperature deposited layer to heat treatment at a second temperature, which is higher than the first temperature, and converting the low-temperature deposited layer into a faceted layer (102); initially growing a GaN based semiconductor layer (103) onto a surface of the faceted layer at a third temperature; and fully growing the GaN based semiconductor layer at a fourth temperature that is lower than the third temperature. By employing the method for fabricating a nitride semiconductor device according to the present invention, it is possible to provide a nitride semiconductor device with high quality and high reliability.

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0≦u, v, w ≦1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0≦x, y, z≦1 and x+y+z=1, by using, as a seed crystal, Cplanes corresponding to top faces of the convexes exposed from the mask film.

Abstract: A method for fabricating a nitride semiconductor device comprising steps of forming a low-temperature deposited layer composed of a Group III-Group V nitride semiconductor containing at least Al onto a surface of substrate (101) at a first temperature; subjecting the low-temperature deposited layer to heat treatment at a second temperature, which is higher than the first temperature, and converting the low-temperature deposited layer into a faceted layer (102); initially growing a GaN based semiconductor layer (103) onto a surface of the faceted layer at a third temperature; and fully growing the GaN based semiconductor layer at a fourth temperature that is lower than the third temperature. By employing the method for fabricating a nitride semiconductor device according to the present invention, it is possible to provide a nitride semiconductor device with high quality and high reliability.

Abstract: After a Group III-V compound semiconductor layer, to which a p-type dopant has been introduced, has been formed over a substrate, the compound semiconductor layer is annealed. In the stage of heating the compound semiconductor layer, atoms, deactivating the p-type dopant, are eliminated from the compound semiconductor layer by creating a temperature gradient in the compound semiconductor layer.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a-first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: A facet-forming layer made of nitride semiconductor containing at least aluminum is formed on a substrate made of gallium nitride (GaN). A facet surface inclined with respect to a C-surface is formed on the surface of the facet-forming layer, and a selective growth layer laterally grows from the inclined facet surface. As a result, the selective growth layer can substantially lattice-match an n-type cladding layer made of n-type AlGaN and grown on the selective growth layer. For example, a laser structure without cracks being generated can be obtained by crystal growth.

Abstract: A semiconductor light-emitting device of Group III-V compound semiconductors includes a quantum well layer, which is formed over a substrate and includes a barrier layer and a well layer that are alternately stacked one upon the other. The band gap of the well layer is narrower than that of the barrier layer. The well layer contains indium and nitrogen, while the barrier layer contains aluminum and nitrogen. In this structure, a tensile strain is induced in the barrier layer, and therefore, a compressive strain induced in the quantum well layer can be reduced. As a result, a critical thickness, at which pits are created, can be increased.

Abstract: A semiconductor light-emitting device of Group III-V compound semiconductors includes a quantum well layer, which is formed over a substrate and includes a barrier layer and a well layer that are alternately stacked one upon the other. The band gap of the well layer is narrower than that of the barrier layer. The well layer contains indium and nitrogen, while the barrier layer contains aluminum and nitrogen. In this structure, a tensile strain is induced in the barrier layer, and therefore, a compressive strain induced in the quantum well layer can be reduced. As a result, a critical thickness, at which pits are created, can be increased.

Abstract: The method for producing a semiconductor of the present invention grows a compound semiconductor on a substrate held by a susceptor provided, in a reaction chamber in accordance with a metalorganic vapor phase epitaxy technique. The method includes the steps of: supplying a Group III source gas containing indium and a Group V source gas containing nitrogen into the reaction chamber; and mixing the Group III and Group V source gases, supplied into the reaction chamber, with each other, and supplying a rare gas as a carrier gas into the reaction chamber so as to carry the mixed source gas onto the upper surface of the substrate.

Abstract: The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AluGavInwN, wherein 0≦u, v, w≦1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlxGayInzN, wherein 0≦x, y, z≦1 and x+y+z=1, by using, as a seed crystal, C planes corresponding to top faces of the convexes exposed from the mask film.