Abstract: It is provided a seed crystal layer, composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof, on an alumina layer on a single crystal substrate. By annealing under reducing atmosphere at a temperature of 950° C. or higher and 1200° C. or lower, convex-concave morphology is formed on a surface of the seed crystal layer so as to have an RMS value of 180 nm to 700 nm measured by an atomic force microscope. On the surface of the seed crystal layer, it is grown a group 13 nitride crystal layer composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of a crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. The crystal of the nitride of the group 13 element contains oxygen atoms in a content of 1×1018 atom/cm3 or less, silicon atoms, manganese atoms, carbon atoms, magnesium atoms and calcium atoms in contents of 1×1017 atom/cm3 or less, chromium atoms in a content of 1×1016 atom/cm3 or less and chlorine atoms in a content of 1×1015 atom/cm3 or less.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. A normal line to the upper surface has an off-angle of 2.0° or less with respect to <0001> direction of the crystal of the nitride of the group 13 element.

Abstract: It is provided a seed crystal layer, composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof, on an alumina layer on a single crystal substrate. By annealing under reducing atmosphere at a temperature of 950° C. or higher and 1200° C. or lower, convex-concave morphology is formed on a surface of the seed crystal layer so as to have an RMS value of 180 nm to 700 nm measured by an atomic force microscope. On the surface of the seed crystal layer, it is grown a group 13 nitride crystal layer composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof.

Abstract: A layer of a crystal of a nitride of a group 13 element selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof includes an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, and the high-luminance light-emitting part has a portion extending along an m-plane of the crystal of the nitride of the group 13 element, when the upper surface is observed by cathode luminescence. The upper surface has an arithmetic average roughness Ra of 0.05 nm or more and 1.0 nm or less.

Abstract: A crystal of a group 13 nitride has an upper surface and lower surface and is composed of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof. When the upper surface of the layer of the crystal of the group 13 nitride is observed by cathode luminescence, the upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. A half value width of reflection at the (0002) plane of a X-ray rocking curve on the upper surface is 3000 seconds or less and 20 seconds or more.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of the crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride.

Abstract: A free-standing substrate of a polycrystalline nitride of a group 13 element contains a plurality of monocrystalline particles having a particular crystal orientation in approximately a normal direction. The polycrystalline nitride of the group 13 element is composed of gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof. The free-standing substrate has a top surface and bottom surface. The free-standing substrate contains at least one of zinc and calcium. A root mean square roughness Rms at the top surface is 3.0 nm or less.

Abstract: An epitaxial substrate for semiconductor elements suppresses leakage current and has a high breakdown voltage. The epitaxial substrate for semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN doped with Zn; a buffer layer formed of a group 13 nitride adjacent to the free-standing substrate; a channel layer formed of a group 13 nitride adjacent to the buffer layer; and a barrier layer formed of a group 13 nitride on an opposite side of the buffer layer with the channel layer therebetween, wherein part of a first region consisting of the free-standing substrate and the buffer layer is a second region containing Si at a concentration of 1×1017cm?3 or more, and a minimum value of a concentration of Zn in the second region is 1×1017cm?3.

Abstract: A free-standing substrate of a polycrystalline nitride of a group 13 element is composed of a plurality of monocrystalline particles having a particular crystal orientation in approximately a normal direction. The free-standing substrate has a top surface and a bottom surface. The polycrystalline nitride of the group 13 element is gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof and contains zinc at a concentration of 1×1017 atoms/cm3 or more and 1×1020 atoms/cm3 or less.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of a crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. A normal line to the upper surface has an off-angle of 2.0° or less with respect to <0001> direction of the crystal of the nitride of the group 13 element.

Abstract: It is provided a layer of a crystal of a nitride of a group 13 element selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof, and the layer includes an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, and the high-luminance light-emitting part has a portion extending along an m-plane of the crystal of the nitride of the group 13 element, in the case that the upper surface is observed by cathode luminescence. The upper surface has an arithmetic average roughness Ra of 0.05 nm or more and 1.0 nm or less.

Abstract: It is provided a layer of a crystal of a group 13 nitride having an upper surface and lower surface and composed of a crystal of the group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof. In the case that the upper surface of the layer of the crystal of the group 13 nitride is observed by cathode luminescence, the upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. A half value width of reflection at (0002) plane of an X-ray rocking curve on the upper surface is 3000 seconds or less and 20 seconds or more.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of a crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride.

Abstract: A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of a crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. The crystal of the nitride of the group 13 element contains oxygen atoms in a content of 1×1018 atom/cm3 or less, silicon atoms, manganese atoms, carbon atoms, magnesium atoms and calcium atoms in contents of 1×1017 atom/cm3 or less, chromium atoms in a content of 1×1016 atom/cm3 or less and chlorine atoms in a content of 1×1015 atom/cm3 or less.

Abstract: An epitaxial substrate for semiconductor elements suppresses leakage current and has a high breakdown voltage. The epitaxial substrate for semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN doped with Zn; a buffer layer formed of a group 13 nitride adjacent to the free-standing substrate; a channel layer formed of a group 13 nitride adjacent to the buffer layer; and a barrier layer formed of a group 13 nitride on an opposite side of the buffer layer with the channel layer therebetween, wherein part of a first region consisting of the free-standing substrate and the buffer layer is a second region containing Si at a concentration of 1×1017cm?3 or more, and a minimum value of a concentration of Zn in the second region is 1×1017cm?3.

Abstract: An epitaxial substrate for semiconductor elements suppresses leakage current and has a high breakdown voltage. The epitaxial substrate for semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN doped with Zn; a buffer layer formed of a group 13 nitride adjacent to the free-standing substrate; a channel layer formed of a group 13 nitride adjacent to the buffer layer; and a barrier layer formed of a group 13 nitride on an opposite side of the buffer layer with the channel layer therebetween, wherein part of a first region consisting of the free-standing substrate and the buffer layer is a second region containing Si at a concentration of 1×1017 cm?3 or more, and a minimum value of a concentration of Zn in the second region is 1×1017 cm?3.

Abstract: An epitaxial substrate for semiconductor elements is provided which suppresses the occurrence of current collapse. The epitaxial substrate for the semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN doped with Zn; a buffer layer adjacent to the free-standing substrate; a channel layer adjacent to the buffer layer; and a barrier layer provided on an opposite side of the buffer layer with the channel layer therebetween, wherein the buffer layer is a diffusion suppressing layer formed of AlpGa1-pN (0.7?p?1) and suppresses diffusion of Zn from the free-standing substrate into the channel layer.

Abstract: Provided is an epitaxial substrate for semiconductor elements which suppresses an occurrence of current collapse. The epitaxial substrate for the semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN being doped with Zn; a buffer layer being adjacent to the free-standing substrate; a channel layer being adjacent to the buffer layer; and a barrier layer being provided on an opposite side of the buffer layer with the channel layer therebetween, wherein the buffer layer is a diffusion suppressing layer formed of Al-doped GaN and suppresses diffusion of Zn from the free-standing substrate into the channel layer.

Abstract: An epitaxial substrate for semiconductor elements which suppresses the occurrence of current collapse. The epitaxial substrate for the semiconductor elements includes: a semi-insulating free-standing substrate formed of GaN doped with Zn; a buffer layer adjacent to the free-standing substrate; a channel layer adjacent to the buffer layer; and a barrier layer provided on an opposite side of the buffer layer with the channel layer provided therebetween, wherein the buffer layer is a diffusion suppressing layer that suppresses the diffusion of Zn from the free-standing substrate into the channel layer.