Abstract: A group III nitride semiconductor device having a gallium nitride based semiconductor film with an excellent surface morphology is provided. A group III nitride optical semiconductor device includes a group III nitride semiconductor supporting base, a GaN based semiconductor region, an active layer, and a GaN semiconductor region. The primary surface of the group III nitride semiconductor supporting base is not any polar plane, and forms a finite angle with a reference plane that is orthogonal to a reference axis extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region, grown on the semipolar primary surface, includes a semiconductor layer of, for example, an n-type GaN based semiconductor doped with silicon. A GaN based semiconductor layer of an oxygen concentration of 5×1016 cm?3 or more provides an active layer, grown on the primary surface, with an excellent crystal quality.

Abstract: A III-nitride semiconductor device has a support base comprised of a III-nitride semiconductor and having a primary surface extending along a first reference plane perpendicular to a reference axis inclined at a predetermined angle ALPHA with respect to the c-axis of the III-nitride semiconductor, and an epitaxial semiconductor region provided on the primary surface of the support base. The epitaxial semiconductor region includes a plurality of GaN-based semiconductor layers. The reference axis is inclined at a first angle ALPHA1 in the range of not less than 10 degrees, and less than 80 degrees from the c-axis of the III-nitride semiconductor toward a first crystal axis, either one of the m-axis and a-axis. The reference axis is inclined at a second angle ALPHA2 in the range of not less than ?0.30 degrees and not more than +0.30 degrees from the c-axis of the III-nitride semiconductor toward a second crystal axis, the other of the m-axis and a-axis.

Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity of high lasing yield, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. In a laser structure, a first surface is opposite to a second surface. The first and second fractured faces extend from an edge of the first surface to an edge of the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

Abstract: Provided is a III-nitride semiconductor laser diode which is capable of lasing at a low threshold. A support base has a semipolar or nonpolar primary surface. The c-axis Cx of a III-nitride is inclined relative to the primary surface. An n-type cladding region and a p-type cladding region are provided above the primary surface of the support base. A core semiconductor region is provided between the n-type cladding region and the p-type cladding region. The core semiconductor region includes a first optical guide layer, an active layer, and a second optical guide layer. The active layer is provided between the first optical guide layer and the second optical guide layer. The thickness of the core semiconductor region is not less than 0.5 ?m. This structure allows the confinement of light into the core semiconductor region without leakage of light into the support base, and therefore enables reduction in threshold current.

Abstract: In step S106, an InXGa1-XN well layer is grown on a semipolar main surface between times t4 and t5 while a temperature in a growth furnace is maintained at temperature TW. In step S107, immediately after completion of the growth of the well layer, the growth of a protective layer covering the main surface of the well layer is initiated at temperature TW. The protective layer is composed of a gallium nitride-based semiconductor with a band gap energy that is higher than that of the well layer and equal to or less than that of a barrier layer. In step S108, the temperature in the furnace is changed from temperatures TW to TB before the barrier layer growth. The barrier layer composed of the gallium nitride-based semiconductor is grown on the protective layer between times t8 and t9 while the temperature in the furnace is maintained at temperature TB.

Abstract: A high electron mobility transistor includes a free-standing supporting base having a III nitride region, a first III nitride barrier layer which is provided on the first III nitride barrier layer, a III nitride channel layer which is provided on the first III nitride barrier layer and forms a first heterojunction with the first III nitride barrier layer, a gate electrode provided on the III nitride channel layer so as to exert an electric field on the first heterojunction, a source electrode on the III nitride channel layer and the first III nitride barrier, and a drain electrode on the III nitride channel layer and the first III nitride barrier. The III nitride channel layer has compressive internal strain, and the piezoelectric field of the III nitride channel layer is oriented in the direction from the supporting base towards the first III nitride barrier layer.

Abstract: A nitride semiconductor light emitting device is provided. A core semiconductor region, a first cladding region, and a second cladding region are mounted on a nonpolar primary surface of a support substrate of GaN which is not the polar plane. The core semiconductor region includes an active layer and a carrier block layer. The first cladding region includes an n-type AlGaN cladding layer and an n-type InAlGaN cladding layer. The n-type InAlGaN cladding layer is provided between the n-type AlGaN cladding layer and the active layer. A misfit dislocation density at an interface is larger than that at an interface. The AlGaN cladding layer is lattice-relaxed with respect to the GaN support substrate and the InAlGaN cladding layer is lattice-relaxed with respect to the AlGaN cladding layer.

Abstract: Provided is a Group III nitride semiconductor laser diode with a cladding layer capable of providing high optical confinement and carrier confinement. An n-type Al0.08Ga0.92N cladding layer is grown so as to be lattice-relaxed on a (20-21)-plane GaN substrate. A GaN optical guiding layer is grown so as to be lattice-relaxed on the n-type cladding layer. An active layer, a GaN optical guiding layer, an Al0.12Ga0.88N electron blocking layer, and a GaN optical guiding layer are grown so as not to be lattice-relaxed on the optical guiding layer. A p-type Al0.08Ga0.92N cladding layer is grown so as to be lattice-relaxed on the optical guiding layer. A p-type GaN contact layer is grown so as not to be lattice-relaxed on the p-type cladding layer, to produce a semiconductor laser. Dislocation densities at junctions are larger than those at the other junctions.

Abstract: For a nitride semiconductor light emitting device, a c-axis vector of hexagonal GaN of a support substrate is inclined to an X-axis direction with respect to a normal axis Nx normal to a primary surface. In a semiconductor region an active layer, a first gallium nitride-based semiconductor layer, an electron block layer, and a second gallium nitride-based semiconductor layer are arranged along the normal axis on the primary surface of the support substrate. A p-type cladding layer is comprised of AlGaN, and the electron block layer is comprised of AlGaN. The electron block layer is subject to tensile strain in the X-axis direction. The first gallium nitride-based semiconductor layer is subject to compressive strain in the X-axis direction. The misfit dislocation density at an interface is smaller than that at an interface. A barrier to electrons at the interface is raised by piezoelectric polarization.

Abstract: Provided is a Group III nitride semiconductor device, which comprises an electrically conductive substrate including a primary surface comprised of a first gallium nitride based semiconductor, and a Group III nitride semiconductor region including a first p-type gallium nitride based semiconductor layer and provided on the primary surface. The primary surface of the substrate is inclined at an angle in the range of not less than 50 degrees, and less than 130 degrees from a plane perpendicular to a reference axis extending along the c-axis of the first gallium nitride based semiconductor, an oxygen concentration Noxg of the first p-type gallium nitride based semiconductor layer is not more than 5×1017 cm?3, and a ratio (Noxg/Npd) of the oxygen concentration Noxg to a p-type dopant concentration Npd of the first p-type gallium nitride based semiconductor layer is not more than 1/10.

Abstract: An object is to provide a nitride-based semiconductor light emitting device capable of preventing a Schottky barrier from being formed at an interface between a contact layer and an electrode. LD 1 is provided as a nitride-based semiconductor light emitting device provided with a GaN substrate 3, a hexagonal GaN-based semiconductor region 5 provided on a primary surface S1 of the GaN substrate 3 and including a light emitting layer 11, and a p-electrode 21 provided on the GaN-based semiconductor region 5 and comprised of metal. The GaN-based semiconductor region 5 includes a contact layer 17 involving strain, the contact layer 17 is in contact with the p-electrode, the primary surface S1 extends along a reference plane S5 inclined at a predetermined inclination angle ? from a plane perpendicular to the c-axis direction of the GaN substrate 3, and the inclination angle ? is either in the range of more than 40° and less than 90° or in the range of not less than 150° and less than 180°.

Abstract: A method for forming a quantum well structure that can reduce the variation in the In composition in the thickness direction of a well layer and a method for manufacturing a semiconductor light emitting element are provided. In a step of forming a quantum well structure (active layer) by alternately growing barrier layers and well layers on a primary surface of a GaN substrate, the well layers are each formed by growing InGaN, the barrier layers are each grown at a first temperature, the well layers are each grown at a second temperature which is lower than that of the first temperature, and when the well layers are each formed, before a starting material gas for Ga (trimethylgallium) is supplied, a starting material gas for In is supplied.

Abstract: A primary surface 23a of a supporting base 23 of a light-emitting diode 21a tilts by an off-angle of 10 degrees or more and less than 80 degrees from the c-plane. A semiconductor stack 25a includes an active layer having an emission peak in a wavelength range from 400 nm to 550 nm. The tilt angle “A” between the (0001) plane (the reference plane SR3 shown in FIG. 5) of the GaN supporting base and the (0001) plane of a buffer layer 33a is 0.05 degree or more and 2 degrees or less. The tilt angle “B” between the (0001) plane of the GaN supporting base (the reference plane SR4 shown in FIG. 5) and the (0001) plane of a well layer 37a is 0.05 degree or more and 2 degrees or less. The tilt angles “A” and “B” are formed in respective directions opposite to each other with reference to the c-plane of the GaN supporting base.

Abstract: A group III nitride semiconductor device having a gallium nitride based semiconductor film with an excellent surface morphology is provided. A group III nitride optical semiconductor device includes a group III nitride semiconductor supporting base, a GaN based semiconductor region, an active layer, and a GaN semiconductor region. The primary surface of the group III nitride semiconductor supporting base is not any polar plane, and forms a finite angle with a reference plane that is orthogonal to a reference axis extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region, grown on the semipolar primary surface, includes a semiconductor layer of, for example, an n-type GaN based semiconductor doped with silicon. A GaN based semiconductor layer of an oxygen concentration of 5×1016 cm?3 or more provides an active layer, grown on the primary surface, with an excellent crystal quality.

Abstract: A method of fabricating a group-III nitride semiconductor laser device includes: preparing a substrate of a hexagonal group-III nitride semiconductor, where the substrate has a semipolar primary surface; forming a substrate product having a laser structure, an anode electrode and a cathode electrode, where the laser structure includes the substrate and a semiconductor region, and where the semiconductor region is formed on the semipolar primary surface; scribing a first surface of the substrate product in part in a direction of the a-axis of the hexagonal group-III nitride semiconductor; and carrying out breakup of the substrate product by press against a second surface of the substrate product, to form another substrate product and a laser bar.

Abstract: In the nitride based semiconductor optical device, the strained well layers extend along a reference plane tilting at a tilt angle ? from the plane that is orthogonal to a reference axis extending in the direction of the c-axis. A gallium nitride based semiconductor layer is adjacent to a light-emitting layer with a negative piezoelectric field and has a band gap larger than that of a barrier layer. The direction of the piezoelectric field in the well layer is directed in a direction from the n-type layer to the p-type layer, and the piezoelectric field in the gallium nitride based semiconductor layer is directed in a direction from the p-type layer to the n-type layer. Consequently, the valence band, not the conduction band, has a dip at the interface between the light-emitting layer and the gallium nitride based semiconductor layer.

Abstract: A group III nitride semiconductor optical device includes: a substrate comprising a group III nitride semiconductor; a first group-III nitride semiconductor region on a primary surface of the substrate; a second group-III nitride semiconductor region on the primary surface of the substrate; and an active layer between the first group-III nitride semiconductor region and the second group-III nitride semiconductor region. The primary surface of the substrate tilts at a tilt angle in the range of 63 degrees to smaller than 80 degrees toward the m-axis of the group III nitride semiconductor from a plane perpendicular to a reference axis extending along the c-axis of the group III nitride semiconductor. The first group-III nitride semiconductor region, the active layer, and the second group-III nitride semiconductor region are arranged in the direction of the normal axis to the primary surface of the substrate. The active layer is configured to produce light having a wavelength in the range of 580 nm to 800 nm.

Abstract: A GaN-based semiconductor light emitting device 11a includes a substrate 13 composed of a GaN-based semiconductor having a primary surface 13a tilting from the c-plane toward the m-axis at a tilt angle ? of more than or equal to 63 degrees and less than 80 degrees, a GaN-based semiconductor epitaxial region 15, an active layer 17, an electron blocking layer 27, and a contact layer 29. The active layer 17 is composed of a GaN-based semiconductor containing indium. The substrate 13 has a dislocation density of 1×107 cm?2 or less. In the GaN-based semiconductor light emitting device 11a provided with the active layer containing indium, a decrease in quantum efficiency under high current injection can be moderated.

Abstract: Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces 27, 29 to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device 11 has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface 17a. In a laser structure 13, a first surface 13a is opposite to a second surface 13b. The first and second fractured faces 27, 29 extend from an edge 13c of the first surface to an edge 13d of the second surface 13b. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

Abstract: A method for forming a quantum well structure that can reduce the variation in the In composition in the thickness direction of a well layer and a method for manufacturing a semiconductor light emitting element are provided. In a step of forming a quantum well structure (active layer) by alternately growing barrier layers and well layers on a primary surface of a GaN substrate, the well layers are each formed by growing InGaN, the barrier layers are each grown at a first temperature, the well layers are each grown at a second temperature which is lower than that of the first temperature, and when the well layers are each formed, before a starting material gas for Ga (trimethylgallium) is supplied, a starting material gas for In is supplied.