Abstract: A nitride semiconductor free-standing substrate includes a surface inclined in a range of 0.03° to 1.0° from a C-plane, and an off-orientation that an angle defined between a C-axis and a tangent at each point on a whole surface of the substrate becomes maximum is displaced in a range of 0.5° to 16° from a particular M-axis orientation of six-fold symmetry M-axis orientations. The substrate does not include a region of ?0.5°<?<+0.5° on the surface, where ? represents a displacement angle of the off-orientation on a surface of the substrate from the particular M-axis orientation.

Abstract: To provide a nitride semiconductor crystal, comprising: laminated homogeneous nitride semiconductor layers, with a thickness of 2 mm or more, wherein the laminated homogeneous nitride semiconductor layers are constituted so that a nitride semiconductor layer with low dopant concentration and a nitride semiconductor layer with high dopant concentration are alternately laminated by two cycles or more.

Abstract: A nitride semiconductor free-standing substrate includes a diameter of not less than 40 mm, a thickness of not less than 100 ?m, a dislocation density of not more than 5×106/cm2, an impurity concentration of not more than 4×1019/cm3, and a nanoindentation hardness of not less than 19.0 GPa at a maximum load in a range of not less than 1 mN and not more than 50 mN.

Abstract: A method for growing a nitride semiconductor has a first step for forming a surface reformation layer on a sapphire substrate, a second step for raising a temperature of the sapphire substrate with the surface reformation layer formed thereon up to a growth temperature of the nitride semiconductor in an atmosphere including ammonia, and a third step for growing a nitride semiconductor layer on a surface of the surface reformation layer. Alternatively, the second step is conducted in an atmosphere including an inert gas, or an atmosphere including the inert gas and hydrogen at a concentration of 10% or less relative to the inert gas.

Abstract: A group III nitride semiconductor free-standing substrate includes an as-grown surface, more than half of a region of the as-grown surface including a single crystal plane. The single crystal plane includes an off-angle inclined in an m-axis or a-axis direction from a C-plane with a group III polarity, or in a c-axis or a-axis direction from an M-plane.

Abstract: There is provided a nitride semiconductor freestanding substrate, with a dislocation density set to be 4×106/cm2 or less in a surface of the nitride semiconductor freestanding substrate, having an in-surface variation of directions of crystal axes along the substrate surface at each point on the substrate surface, with this variation of the directions of the crystal axes along the substrate surface set to be in a range of ±0.2° or less.

Abstract: A n-type layer, a multiquantum well active layer comprising a plurality of pairs of an InGaN well layer/InGaN barrier layer, and a p-type layer are laminated on a substrate to provide a nitride semiconductor light emitting element. A composition of the InGaN barrier included in the multiquantum well active layer is expressed by InxGa1-xN (0.04?x?0.1), and a total thickness of InGaN layers comprising an In composition ratio within a range of 0.04 to 0.1 in the light emitting element including the InGaN barrier layers is not greater than 60 nm.

Abstract: A technique of ensuring compatibility between the method of improving the light extraction efficiency by roughening the surface of a LED structure, and the method of avoiding the adverse effect of a low-cost electrode pad ((1) forming a current distribution layer by a transparent conductive film made of metal or metal oxide, and (2) forming a flip chip structure). A light emitting diode has at least an n-type semiconducting layer, an active layer composed of 30 or less quantum well layers, and a p-type semiconducting layer provided on a substrate, wherein the surface of the semiconductor lamination structure contains a flat portion and a plurality of bores.

Abstract: A zinc-blende nitride semiconductor free-standing substrate has a front surface and a back surface opposite the front surface. The distance between the front and back surfaces is not less than 200 ?m. The area ratio of the zinc-blende nitride semiconductor to the front surface is not less than 95%.

Abstract: A method for growing a nitride semiconductor has a first step for forming a surface reformation layer on a sapphire substrate, a second step for raising a temperature of the sapphire substrate with the surface reformation layer formed thereon up to a growth temperature of the nitride semiconductor in an atmosphere including ammonia, and a third step for growing a nitride semiconductor layer on a surface of the surface reformation layer. Alternatively, the second step is conducted in an atmosphere including an inert gas, or an atmosphere including the inert gas and hydrogen at a concentration of 10% or less relative to the inert gas.

Abstract: A n-type layer, a multiquantum well active layer comprising a plurality of pairs of an InGaN well layer/InGaN barrier layer, and a p-type layer are laminated on a substrate to provide a nitride semiconductor light emitting element. A composition of the InGaN barrier included in the multiquantum well active layer is expressed by InxGa1-xN (0.04?x?0.1), and a total thickness of InGaN layers comprising an In composition ratio within a range of 0.04 to 0.1 in the light emitting element including the InGaN barrier layers is not greater than 60 nm.

Abstract: A method for producing a nitride semiconductor crystal comprising steps (a), (b) and (c), which steps follow in sequence as follows: a step (a) for forming fine crystal particles made of a nitride semiconductor on a substrate; a step (b) for forming a nitride semiconductor island structure having a plurality of facets inclined relative to a surface of the substrate using the fine crystal particles as nuclei; and a step (c) for causing the nitride semiconductor island structure to grow in a direction parallel with a surface of the substrate to merge a plurality of the nitride semiconductor island structures with each other, thereby forming a nitride semiconductor crystal layer having a flat surface; the steps (a)-(c) being continuously conducted in the same growing apparatus.

Abstract: A technique of ensuring compatibility between the method of improving the light extraction efficiency by roughening the surface of a LED structure, and the method of avoiding the adverse effect of a low-cost electrode pad ((1) forming a current distribution layer by a transparent conductive film made of metal or metal oxide, and (2) forming a flip chip structure). A light emitting diode comprises at least an n-type semiconducting layer, an active layer composed of 30 or less quantum well layers, and a p-type semiconducting layer provided on a substrate, wherein the surface of the semiconductor lamination structure contains a flat portion and a plurality of bores.

Abstract: A method for producing a nitride semiconductor comprising growing at least first to third nitride semiconductor layers on a substrate; said first nitride semiconductor layer being grown at 400–600° C.; and said second and third nitride semiconductor layers being grown on said first nitride semiconductor layer at 700–1,300° C. after heat-treating said first nitride semiconductor layer at 700–1,300° C.; used as a carrier gas supplied near said substrate together with a starting material gas being a hydrogen/nitrogen mixture gas containing 63% or more by volume of hydrogen during growing said second nitride semiconductor layer, and a hydrogen/nitrogen mixture gas containing 50% or more by volume of nitrogen during growing said third nitride semiconductor layer; and said second nitride semiconductor layer being formed to a thickness of more than 1 ?m.

Abstract: A method for producing a nitride semiconductor comprising growing at least first to third nitride semiconductor layers on a substrate; said first nitride semiconductor layer being grown at 400-600° C.; and said second and third nitride semiconductor layers being grown on said first nitride semiconductor layer at 700-1,300° C. after heat-treating said first nitride semiconductor layer at 700-1,300° C.; used as a carrier gas supplied near said substrate together with a starting material gas being a hydrogen/nitrogen mixture gas containing 63% or more by volume of hydrogen during growing said second nitride semiconductor layer, and a hydrogen/nitrogen mixture gas containing 50% or more by volume of nitrogen during growing said third nitride semiconductor layer; and said second nitride semiconductor layer being formed to a thickness of more than 1 ?m.

Abstract: A method for producing a nitride semiconductor crystal comprising a step (a) for forming fine crystal particles made of a nitride semiconductor on a substrate; a step (b) for forming a nitride semiconductor island structure having a plurality of facets inclined relative to a surface of the substrate with the fine crystal particles as nuclei; and a step (c) for causing the nitride semiconductor island structure to grow in a direction parallel with a surface of the substrate to merge a plurality of the nitride semiconductor island structures with each other, thereby forming a nitride semiconductor crystal layer having a flat surface; the steps (a)-(c) being continuously conducted in the same growing apparatus.