Abstract: Provided are: a GaN substrate wafer having a crystallinity suitable as a substrate for a semiconductor device as well as an improved productivity; and a method of producing the same. The GaN substrate wafer is a (0001)-oriented GaN substrate wafer that includes a first region arranged on an N-polar side and a second region arranged on a Ga-polar side via a regrowth interface therebetween. In this GaN substrate wafer, the second region has a minimum thickness of not less than 20 ?m, the concentration of at least one element selected from Li, Na, K, F, Cl, Br, and I in the first region is 1×1015 atoms/cm3 or higher, and the second region satisfies one or more conditions selected from the following (a) to (c): (a) the Si concentration is 5×1016 atoms/cm3 or higher; (b) the O concentration is 3×1016 atoms/cm3 or lower; and (c) the H concentration is 1×1017 atoms/cm3 or lower.

Abstract: The purpose of the present invention is to provide a grinding material which has a superior grinding rate and planarizing accuracy, with the grinding rate being less likely to be reduced over a relatively long period of time. The present invention is directed to a grinding material including a base, a grinding layer overlaid on a front face side of the base and including grinding grains and a binder for the grinding grains, and an adhesion layer overlaid on a back face side of the base, in which the grinding grains are diamond grinding grains, a wear quantity of the grinding layer as determined by a Taber abrasion test is no less than 0.03 g and no greater than 0.18 g, and, an Asker D hardness measured from a front face side of the grinding layer is no less than 80° and no greater than 98°.

Abstract: The purpose of the present invention is to provide a grinding material which has a superior grinding rate and planarizing accuracy, with the grinding rate being less likely to be reduced over a relatively long period of time. The present invention is directed to a grinding material including a base, a grinding layer overlaid on a front face side of the base and including grinding grains and a binder for the grinding grains, and an adhesion layer overlaid on a back face side of the base, in which the grinding grains are diamond grinding grains, a wear quantity of the grinding layer as determined by a Taber abrasion test is no less than 0.03 g and no greater than 0.18 g, and, an Asker D hardness measured from a front face side of the grinding layer is no less than 80° and no greater than 98°.

Abstract: Disclosed herein is a light emitting diode (LED) including: a gallium nitride substrate; a gallium nitride-based first contact layer disposed on the gallium nitride substrate; a gallium nitride-based second contact layer; an active layer having a multi-quantum well structure and disposed between the first and second contact layers; and a super-lattice layer having a multilayer structure and disposed between the first contact layer and the active layer. By employing the gallium nitride substrate, the crystallinity of the semiconductor layers can be improved, and in addition, by disposing the super-lattice layer between the first contact layer and the active layer, a crystal defect that may be generated in the active layer can be prevented.

Abstract: An conductive paste comprises inorganic particles having alkylamine with 6 or less of carbon number on at least a portion of a surface, a polymer dispersant having a pigment affinity group in a main chain and/or a plurality of side chains, and, that comprising a polymer with a comb structure having a plurality of side chains constituting a solvation portion, a polymer having a plurality of pigment affinity portions made from a pigment affinity group in the main chain or a straight-chain polymer having a pigment affinity portion made from a pigment affinity group in one terminal of the main chain, a dispersion medium, wherein a weight reduction percentage at the time of heating solid content of the conductive paste from room temperature to 500° C. by thermal analysis is 15% by weight or less.

Abstract: To provide a bonding composition where high joint strength can be obtained due to joining at a comparatively low temperature and under a pressureless condition, and, that is also equipped with thermal resistance that is difficult to cause a reduction of joint strength due to decomposition, deterioration and/or the like of a resin component at the time of an increase of an operating temperature, and to provide a bonding composition particularly containing metallic particles.

Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.

Abstract: Provided is a composition for metal bonding, especially a bonding composition containing metal particles, which is capable of achieving high bonding strength by bonding at a relatively low temperature without the application of a pressure, and which has heat resistance and is thus not susceptible to decrease in the bonding strength due to decomposition or deterioration of a resin component when the service temperature thereof is increased. A bonding composition which is characterized by containing two or more kinds of metal particles having different average particle diameters, an organic component and a dispersant, and which is also characterized in that the particle diameter ratio of the average particle diameter (DS) of metal particles (S) that have the smallest average particle diameter to the average particle diameter (DL) of metal particles (L) that have the largest average particle diameter, namely DS/DL is from 1×10-4 to 0.5.

Abstract: A nitride LED having improved light extraction efficiency and/or axial luminous intensity is provided. The nitride LED contains a nitride semiconductor substrate having, on a front face thereof, a light-emitting structure made of a nitride semiconductor, wherein a roughened region is provided on a back face of the substrate, the roughened region has a plurality of protrusions, each of the plurality of protrusions has a top point or top plane and has a horizontal cross-section which is circular, except in areas where the protrusion is tangent to other neighboring protrusions, and which has a surface area that decreases on approaching the top point or top plane, the plurality of protrusions are arranged such that any one protrusion is in contact with six other protrusions, and light generated in the light-emitting structure is output to the exterior through the roughened region.

Abstract: To provide a bonding composition where high joint strength can be obtained due to joining at a comparatively low temperature and under a pressureless condition, and, that is also equipped with thermal resistance that is difficult to cause a reduction of joint strength due to decomposition, deterioration and/or the like of a resin component at the time of an increase of an operating temperature, and to provide a bonding composition particularly containing metallic particles.

Abstract: An conductive paste comprises inorganic particles having alkylamine with 6 or less of carbon number on at least a portion of a surface, a polymer dispersant having a pigment affinity group in a main chain and/or a plurality of side chains, and, that comprising a polymer with a comb structure having a plurality of side chains constituting a solvation portion, a polymer having a plurality of pigment affinity portions made from a pigment affinity group in the main chain or a straight-chain polymer having a pigment affinity portion made from a pigment affinity group in one terminal of the main chain, a dispersion medium, wherein a weight reduction percentage at the time of heating solid content of the conductive paste from room temperature to 500° C. by thermal analysis is 15% by weight or less.

Abstract: Provided is a novel method for producing an m-plane nitride-based LED, the method making it possible to obtain an m-plane nitride-based LED reduced in forward voltage. The method comprising (i) a step of forming an active layer consisting of a nitride semiconductor over an n-type nitride semiconductor layer in which an angle between the thickness direction and the m-axis of a hexagonal crystal is 10 degrees or less, (ii) a step of forming an AlGaN layer doped with a p-type impurity over the active layer, (iii) a step of forming a contact layer consisting of InGaN is formed on the surface of the AlGaN layer, and (iv) a step of forming an electrode on the surface of the contact layer.

Abstract: Disclosed herein is a light emitting diode (LED) including: a gallium nitride substrate; a gallium nitride-based first contact layer disposed on the gallium nitride substrate; a gallium nitride-based second contact layer; an active layer having a multi-quantum well structure and disposed between the first and second contact layers; and a super-lattice layer having a multilayer structure and disposed between the first contact layer and the active layer. By employing the gallium nitride substrate, the crystallinity of the semiconductor layers can be improved, and in addition, by disposing the super-lattice layer between the first contact layer and the active layer, a crystal defect that may be generated in the active layer can be prevented.

Abstract: Disclosed herein are a high efficiency light emitting diode and a method of fabricating the same. The light emitting diode includes a semiconductor stacked structure disposed on the support substrate and including a gallium nitride-based p-type semiconductor layer, a gallium nitride-based active layer, and a gallium nitride-based n-type semiconductor layer; and a reflecting layer disposed between the support substrate and the semiconductor stacked structure, wherein the semiconductor stacked structure includes a plurality of protrusions having a truncated cone shape and fine cones formed on top surfaces of the protrusions. By this configuration, light extraction efficiency of the semiconductor stacked structure having low dislocation density can be improved.

Abstract: Provided is a composition for bonding, in particular, a composition for bonding which contains metal particles, said composition for bonding enabling the achievement of high bonding strength by bonding at a relatively low temperature and having such heat resistance that a decrease in the bonding strength does not easily occur due to &composition, deterioration or the like of a resin component when service temperature is increased. This composition for bonding is characterized by containing inorganic particles and an organic material that contains an amine and/or a carboxylic acid and adheres to at least a part of the surface of each inorganic particle, and is also characterized in that the weight loss rate when heated from room temperature to 200°c. is 33-69% and the weight loss rate when heated from 200° c. to 300° c. is 24-50% as determined by thermal analysis.

Abstract: A nitride LED having improved light extraction efficiency and/or axial luminous intensity is provided. The nitride LED contains a nitride semiconductor substrate having, on a front face thereof, a light-emitting structure made of a nitride semiconductor, wherein a roughened region is provided on a back face of the substrate, the roughened region has a plurality of protrusions, each of the plurality of protrusions has a top point or top plane and has a horizontal cross-section which is circular, except in areas where the protrusion is tangent to other neighboring protrusions, and which has a surface area that decreases on approaching the top point or top plane, the plurality of protrusions are arranged such that any one protrusion is in contact with six other protrusions, and light generated in the light-emitting structure is output to the exterior through the roughened region.

Abstract: A production process for a nitride semiconductor crystal, comprising growing a semiconductor layer on a seed substrate to obtain a nitride semiconductor crystal, wherein the seed substrate comprises a plurality of seed substrates made of the same material, at least one of the plurality of seed substrates differs in the off-angle from the other seed substrates, and a single semiconductor layer is grown by disposing the plurality of seed substrates in a semiconductor crystal production apparatus, such that when the single semiconductor layer is grown on the plurality of seed substrates, the off-angle distribution in the single semiconductor layer becomes smaller than the off-angle distribution in the plurality of seed substrates.

Abstract: Disclosed is a method of manufacturing a GaN-based material having high thermal conductivity. A gallium nitride-based material is grown by HVPE (Hydride Vapor Phase Epitaxial Growth) by supplying a carrier gas (G1) containing H2 gas, GaCl gas (G2), and NH3 gas (G3) to a reaction chamber (10), and setting the growth temperature at 900 (° C.) (inclusive) to 1,200 (° C.) (inclusive), the growth pressure at 8.08×104 (Pa) (inclusive) to 1.21×105 (Pa) (inclusive), the partial pressure of the GaCl gas (G2) at 1.0×104 (Pa) (inclusive) to 1.0×104 (Pa) (inclusive), and the partial pressure of the NH3 gas (G3) at 9.1×102 (Pa) (inclusive) to 2.0×104 (Pa) (inclusive).

Abstract: A method to make gallium nitride-based material by Hydride Vapor Phase Epitaxial Growth is provided.

Abstract: A gallium nitride-based material prepared by a vertical Hydride Vapor Phase Epitaxial Growth method which has thermal conductivity of at least 2.8×102 W/m·K at 25° C. is provided.