Abstract: A group III nitride crystal substrate has a main surface and a back surface opposite to the main surface. The average dislocation density of the main surface and the average dislocation density of the back surface are less than or equal to 6.0×105 cm?2. Furthermore, the difference between the average dislocation density of the main surface and the average dislocation density of the back surface is less than or equal to 5.0×104 cm?2. The warpage of the crystal axis of the main surface has a radius of curvature of more than or equal to 30 m.

Abstract: A RAMO4 substrate includes a single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on one surface of the RAMO4 substrate, a satin-finish surface is provided on another surface. The satin-finish surface has surface roughness which is larger than that of the epitaxially-grown surface.

Abstract: To provide a high-quality group III nitride semiconductor. A group III nitride semiconductor including an n-GaN layer composed of AlxGa1-xN (0?x<1), an InGaN layer disposed on the n-GaN layer and composed of InGaN, an n-AlGaN layer disposed on the InGaN layer and composed of n-type AlyGa1-yN (0?y<1), and a functional layer disposed on the n-AlGaN layer, wherein the concentration of Mg in the n-GaN layer is higher than the concentration of Mg in the n-AlGaN layer.

Abstract: An object is to provide a high-quality ScAlMgO4 single crystal and a device. The ScAlMgO4 single crystal includes Sc, Al, Mg, and O, in which the atomic percentage ratio of Mg to Al, Mg/Al (atom %/atom %), as measured by an inductively coupled plasma emission spectrometric method, is more than 1 and less than 1.1.

Abstract: To provide a high-quality group III nitride semiconductor. A group III nitride semiconductor including an n-GaN layer composed of AlxGa1?xN(0?x<1), an InGaN layer disposed on the n-GaN layer and composed of InGaN, an n-AlGaN layer disposed on the InGaN layer and composed of n-type AlyGa1?yN (0?y<1), and a functional layer disposed on the n-AlGaN layer, wherein the concentration of Mg in the n-GaN layer is higher than the concentration of Mg in the n-AlGaN layer.

Abstract: An object is to provide a high-quality ScAlMgO4 single crystal and a device. The ScAlMgO4 single crystal includes Sc, Al, Mg, and O, in which the atomic percentage ratio of Mg to Al, Mg/Al (atom %/atom %), as measured by an inductively coupled plasma emission spectrometric method, is more than 1 and less than 1.1.

Abstract: An RAMO4 substrate including a single crystal represented by a general formula RAMO4, wherein R represents one or more trivalent elements selected from a group consisting of Sc, In, Y, and lanthanide elements, A represents one or more trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd, in which a main plane of the RAMO4 substrate has an off-angle a tilted ?a° with respect to an M-axis direction from a C-plane and 0.05°?|?a|?0.8° is satisfied.

Abstract: A RAMO4 substrate is formed from single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected form a group consisting of Hg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on at least one surface of the RAMO4 substrate. The epitaxially-grown surface includes a plurality of cleavage surfaces which are regularly distributed, and are separated from each other.

Abstract: An RAMO4 substrate including a single crystal represented by a general formula RAMO4, wherein R represents one or more trivalent elements selected from a group consisting of Sc, In, Y, and lanthanide elements, A represents one or more trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd, in which a main plane of the RAMO4 substrate has an off-angle a tilted ?a° with respect to an M-axis direction from a C-plane and 0.05°?|?a|?0.8° is satisfied.

Abstract: A Group III nitride semiconductor containing: a RAMO4 substrate containing a single crystal represented by the general formula RAMO4 (wherein R represents one or a plurality of trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, A represents one or a plurality of trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or a plurality of divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd), and a Group III nitride crystal disposed above the RAMO4 substrate, having therebetween a dissimilar film that contains a material different from the RAMO4 substrate, and has plural openings.

Abstract: On an RAMO4 substrate containing a single crystal represented by the general formula RAMO4 (wherein R represents one or a plurality of trivalent elements selected from a group of elements including: Sc, In, Y, and a lanthanoid element, A represents one or a plurality of trivalent elements selected from a group of elements including: Fe(III), Ga, and Al, and M represents one or a plurality of divalent elements selected from a group of elements including: Mg, Mn, Fe(II), Co, Cu, Zn, and Cd), a buffer layer containing a nitride of In and a Group III element except for In is formed, and a Group III nitride crystal is formed on the buffer layer.

Abstract: On an RAMO4 substrate containing a single crystal represented by the general formula RAMO4 (wherein R represents one or a plurality of trivalent elements selected from a group of elements including: Sc, In, Y, and a lanthanoid element, A represents one or a plurality of trivalent elements selected from a group of elements including: Fe(III), Ga, and Al, and M represents one or a plurality of divalent elements selected from a group of elements including: Mg, Mn, Fe(II), Co, Cu, Zn, and Cd), a buffer layer containing a nitride of In and a Group III element except for In is formed, and a Group III nitride crystal is formed on the buffer layer.

Abstract: A Group III nitride semiconductor containing: a RAMO4 substrate containing a single crystal represented by the general formula RAMO4 (wherein R represents one or a plurality of trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, A represents one or a plurality of trivalent elements selected from the group consisting of Fe (III), Ga, and Al, and M represents one or a plurality of divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd), and a Group III nitride crystal disposed above the RAMO4 substrate, having therebetween a dissimilar film that contains a material different from the RAMO4 substrate, and has plural openings.

Abstract: A RAMO4 substrate is formed from single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected form a group consisting of Hg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on at least one surface of the RAMO4 substrate. The epitaxially-grown surface includes a plurality of cleavage surfaces which are regularly distributed, and are separated from each other.

Abstract: A RAMO4 substrate includes a single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on at least one surface of the RAMO4 substrate. An unevenness having a height of 500 nm or more is not provided on the epitaxially-grown surface.

Abstract: A RAMO4 substrate includes a single crystal represented by a formula of RAMO4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on one surface of the RAMO4 substrate, a satin-finish surface is provided on another surface. The satin-finish surface has surface roughness which is larger than that of the epitaxially-grown surface.

Abstract: The present invention improves luminous efficiency of a nitride semiconductor light-emitting element. In the nitride semiconductor light-emitting element, a non-polar or semi-polar Alx2Iny2Gaz2N layer having a thickness of t1 is interposed between the Alx1Iny1Gaz1N layer included in the p-type nitride semiconductor layer and the active layer (0<x2?1, 0?y2<1, 0<z2<1, x2+y2+z2=1). The Alx2Iny2Gaz2N layer has first and second interfaces located close to or in contact with the active layer and the Alx1Iny1Gaz1N layer, respectively. The Alx2Iny2Gaz2N layer has a hydrogen concentration distribution along its thickness direction in the inside thereof in such a manner that the hydrogen concentration is increased from the first interface to a thickness t2 (t2<t1), reaches a peak at the thickness t2, and is decreased from the thickness t2 to the second interface. Magnesium contained in the Alx1Iny1Gaz1N layer is prevented from being diffused into the active layer to improve the luminous efficiency.

Abstract: The present invention improves luminous efficiency of a nitride semiconductor light-emitting element. In the nitride semiconductor light-emitting element, a non-polar or semi-polar Alx2Iny2Gaz2N layer having a thickness of t1 is interposed between the Alx1Iny1Gaz1N layer included in the p-type nitride semiconductor layer and the active layer (0<x2?1, 0?y2<1, 0<z2<1, x2+y2+z2=1). The Alx2Iny2Gaz2N layer has first and second interfaces located close to or in contact with the active layer and the Alx1Iny1Gaz1N layer, respectively. The Alx2Iny2Gaz2N layer has a hydrogen concentration distribution along its thickness direction in the inside thereof in such a manner that the hydrogen concentration is increased from the first interface to a thickness t2 (t2<t1), reaches a peak at the thickness t2, and is decreased from the thickness t2 to the second interface. Magnesium contained in the Alx1Iny1Gaz1N layer is prevented from being diffused into the active layer to improve the luminous efficiency.

Abstract: A nitride semiconductor laser diode includes a substrate of n-type GaN, and a multilayer structure including an n-type cladding layer of AlxGa1-xN (where 0<x<1) formed on and in contact with a main surface of the substrate, an MQW active layer formed on the n-type cladding layer, and a p-type cladding layer formed on the MQW active layer. The main surface of the substrate is oriented at an angle ranging from 0.25° to 0.7° with respect to a (0001) plane of a plane orientation. The composition x of the AlxGa1-xN is in a range from 0.025 to 0.04.

Abstract: A nitride semiconductor laser diode includes a substrate of n-type GaN, and a multilayer structure including an n-type cladding layer of AlxGa1-x N (where 0<x<1) formed on and in contact with a main surface of the substrate, an MQW active layer formed on the n-type cladding layer, and a p-type cladding layer formed on the MQW active layer. The main surface of the substrate is oriented at an angle ranging from 0.25° to 0.7° with respect to a (0001) plane of a plane orientation. The composition x of the AlxGa1-xN is in a range from 0.025 to 0.04.