Abstract: A sputtering target includes a gallium nitride-based crystalline body composed of a plurality of gallium nitride-based monocrystalline grains whose c-axes are orientated in a direction normal to a predetermined surface. The gallium nitride-based crystalline body has a total oxygen concentration of 150 mass ppm or lower, and the gallium nitride-based monocrystalline grains have oxygen concentrations of 2×1017 cm?3 or higher measured by dynamic SIMS method.

Abstract: Group-III element nitride semiconductor substrate including a first surface and a second surface that are easy to visually distinguish from each other. An end portion is easily detected with an optical sensor, a large effective area (area that can be used in device production) can be secured, and warping of the entirety of the substrate is reduced. A Group-III element nitride semiconductor substrate includes a first surface; and a second surface, wherein the first surface is a mirror surface, the second surface has a second-surface central region and a second-surface outer peripheral region, the second-surface central region is a mirror surface, and the second-surface outer peripheral region is a non-mirror surface.

Abstract: A Group-III element nitride semiconductor substrate includes: a first surface; and a second surface, wherein warping of a crystal plane of the first surface has a plurality of extremes.

Abstract: A Group-III element nitride semiconductor substrate includes: a first surface; and a second surface. The Group-III element nitride semiconductor substrate has a c-plane tilted with respect to a direction of the first surface, and a direction of the tilt falls between a <1-100> direction and a <11-20> direction.

Abstract: Group-III element nitride semiconductor substrate including a first surface and a second surface that are easy to visually distinguish from each other. An end portion is easily detected with an optical sensor, a large effective area (area that can be used in device production) can be secured, and warping of the entirety of the substrate is reduced. A Group-III element nitride semiconductor substrate includes a first surface; and a second surface, wherein the first surface is a mirror surface, the second surface has a second-surface central region and a second-surface outer peripheral region, the second-surface central region is a mirror surface, and the second-surface outer peripheral region is a non-mirror surface.

Abstract: There is provided a large-diameter Group-III element nitride semiconductor substrate including a first surface and a second surface, in which, despite its large diameter, variations in quality in the first surface are suppressed. A Group-III element nitride semiconductor includes: a first surface; and a second surface, wherein the Group-III element nitride semiconductor substrate has a diameter of 100 mm or more, and wherein the Group-III element nitride semiconductor substrate has a coefficient of variation of a yellow luminescence intensity in a range corresponding to 88% or more of an entire region of the first surface of 0.3 or less based on a photoluminescence spectrum obtained through photoluminescence measurement of a range of the entire region of the first surface.

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: An MEMS device includes: a first member; a second member forming a sealed space with the first member therebetween; and a third member disposed between the first member and the second member and joined to the first member and the second member, in which the third member has lower rigidity than rigidity of the first member and the second member, and the third member is provided with a communication portion that establishes communication between the sealed space and an external space.

Abstract: An ultrasonic element includes an element substrate including a first surface, a second surface having a front-back relation with the first surface, an opening section piercing through the element substrate from the first surface to the second surface, and a partition wall section surrounding the opening section, a supporting film provided on the first surface of the element substrate to cover the opening section and including a third surface facing the opening section and a fourth surface having a front-back relation with the third surface, a piezoelectric element provided on the fourth surface of the supporting film and disposed in a region overlapping the opening section of the supporting film in a plan view from a film thickness direction extending from the third surface to the fourth surface, a sealing plate provided to be opposed to the fourth surface of the supporting film and joined to the supporting film by an adhesive member via a beam section projecting toward the supporting film, and a wall sectio

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: It is provided a layer of a nitride of a group 13 element having a first main face and second main face. The layer of the nitride of the group 13 element includes a first void-depleted layer provided on the side of the first main face, a second void-depleted layer provided on the side of the second main face, and the void-distributed layer provided between the first void-depleted layer and second void-depleted layer.

Abstract: A piezoelectric element has a first electrode layer, a piezoelectric layer on the first electrode layer, a second electrode layer on the piezoelectric layer, a third electrode layer on part of the second electrode layer and including third metal, and an insulating layer covering at least a part of the piezoelectric layer not provided with the second electrode layer and having an aperture exposing a part of the second electrode layer. The second electrode layer has a first layer including first metal and a second layer including second metal on the first layer. The second layer is exposed in the aperture. A difference in standard redox potential between the second metal and the third metal is smaller than a difference in standard redox potential between the first metal and the third metal.

Abstract: An underlying substrate including a seed crystal layer of a group 13 nitride, wherein projections and recesses repeatedly appear in stripe shapes at a principal surface of the seed crystal layer, and the projections have a level difference of 0.3 to 40 ?m and a width of 5 to 100 ?m, and the recesses have a bottom thickness of 2 ?m or more and a width of 50 to 500 ?m.

Abstract: A group 13 nitride layer is composed of a polycrystalline group 13 nitride and is constituted by a plurality of monocrystalline particles having a particular crystal orientation approximately in a normal direction. The group 13 nitride comprises gallium nitride, aluminum nitride, indium nitride or the mixed crystal thereof. The group 13 nitride layer includes an upper surface and a bottom surface, and a full width at half maximum of a (1000) plane reflection of X-ray rocking curve on the upper surface is 20000 seconds or less and 1500 seconds or more.

Abstract: A method of producing a functional device has an etched gallium nitride layer and a functional layer having a nitride of a group 13 element. The method includes providing a body comprising a surface gallium nitride layer, performing a dry etching treatment of a surface of the surface gallium nitride layer to provide the etched gallium nitride layer using a plasma etching system comprising an inductively coupled plasma generating system, introducing an etchant during the dry etching treatment, the etchant consisting essentially of a fluorine-based gas, and forming the functional layer on a surface of the etched gallium nitride layer.

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 MEMS device includes: a first member; a second member forming a sealed space with the first member therebetween; and a third member disposed between the first member and the second member and joined to the first member and the second member, in which the third member has lower rigidity than rigidity of the first member and the second member, and the third member is provided with a communication portion that establishes communication between the sealed space and an external space.

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: There is provided a self-supporting polycrystalline gallium nitride substrate having excellent characteristics such as high luminous efficiency and high conversion efficiency when used for devices, such as light emitting devices and solar cells. The self-supporting polycrystalline gallium nitride substrate is composed of gallium nitride-based single crystal grains having a specific crystal orientation in a direction approximately normal to the substrate, and has a top surface and a bottom surface. The crystal orientations of individual gallium nitride-based single crystal grains as determined from inverse pole figure mapping by electron backscatter diffraction (EBSD) analysis on the top surface are distributed at various tilt angles from the specific crystal orientation, in which the average tilt angle thereof is 0.1° or more and less than 1° and the cross-sectional average diameter DT of the gallium nitride-based single crystal grains at the outermost surface exposed on the top surface is 10 ?m or more.

Abstract: A piezoelectric device includes a substrate having opening portions, a vibrating plate provided to overlap with the substrate and having a plurality of vibrating regions overlapping with the opening portions in a plan view as seen from a thickness direction of the substrate, piezoelectric elements provided in the vibrating regions, and bypass wires provided outside of the vibrating regions of the vibrating plate and electrically coupled to the plurality of piezoelectric elements, wherein slits penetrating the bypass wires in the thickness direction are provided in the bypass wires.