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: 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 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 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: 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 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: 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 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: Provided is a III-nitride semiconductor laser allowing for provision of a low threshold with use of a semipolar plane. A primary surface 13a of a semiconductor substrate 13 is inclined at an angle of inclination AOFF in the range of not less than 50 degrees and not more than 70 degrees toward the a-axis direction of GaN with respect to a reference plane perpendicular to a reference axis Cx along the c-axis direction of GaN. A first cladding layer 15, an active layer 17, and a second cladding layer 19 are provided on the primary surface 13a of the semiconductor substrate 13. The well layers 23a of the active layer 17 comprise InGaN. A polarization degree P in the LED mode of emission from the active layer of the semiconductor laser that reaches lasing is not less than ?1 and not more than 0.1.

Abstract: Provided is a nitride semiconductor light emitting device including a light emitting layer above a GaN support base with a semipolar surface and allowing for suppression of reduction in luminous efficiency due to misfit dislocations. A nitride semiconductor light emitting device 11 has a support base 13 comprised of a hexagonal gallium nitride, an n-type gallium nitride-based semiconductor layer 15 including an InX1AlY1Ga1-X1-Y1N (0<X1<1, 0<Y1<1, X1+Y1<1) layer 21, a light emitting layer 17, and a p-type gallium nitride-based semiconductor layer 19. This InAlGaN layer 21 is provided between a semipolar primary surface 13a and the light emitting layer 17. Since the bandgap E of the InAlGaN layer 21 is not less than the bandgap E of gallium nitride, a confinement effect of carriers and light in the light emitting layer 17 is provided.

Abstract: A nitride semiconductor light-emitting element 11 is one for generating light containing a wavelength component in an ultraviolet region. The nitride semiconductor light-emitting element 11 has an active region 17 including InX1AlY1Ga1-X1-Y1N well layers 13 (1>X1>0 and 1>Y1>0) and InX2AlY2Ga1-X2-Y2N barrier layers 15 (1>X2>0 and 1>Y2>0). An energy gap difference Eg1 between the InX1AlY1Ga1-X1-Y1N well layers 13 and the InX2AlY2Ga1-X2-Y2N barrier layers 15 is not less than 2.4×10?20 J nor more than 4.8×10?20 J.

Abstract: In the nitride based semiconductor optical device LE1, the strained well layers 21 extend along a reference plane SR1 tilting at a tilt angle ? from the plane that is orthogonal to a reference axis extending in the direction of the c-axis. The tilt angle ? is in the range of greater than 59 degrees to less than 80 degrees or greater than 150 degrees to less than 180 degrees. A gallium nitride based semiconductor layer P is adjacent to a light-emitting layer SP? 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 W3 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 P 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 SP? and the gallium nitride based semiconductor layer P.

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 11a includes a group III nitride semiconductor supporting base 13, a GaN based semiconductor region 15, an active layer active layer 17, and a GaN semiconductor region 19. The primary surface 13a of the group III nitride semiconductor supporting base 13 is not any polar plane, and forms a finite angle with a reference plane Sc that is orthogonal to a reference axis Cx extending in the direction of a c-axis of the group III nitride semiconductor. The GaN based semiconductor region 15 is grown on the semipolar primary surface 13a. A GaN based semiconductor layer 21 of the GaN based semiconductor region 15 is, for example, an n-type GaN based semiconductor, and the n-type GaN based semiconductor is doped with silicon.

Abstract: In the method of fabricating a nitride-based semiconductor optical device by metal-organic chemical vapor deposition, a barrier layer is grown at a first temperature while supplying a gallium source to a reactor. The barrier layer comprises a first gallium nitride-based semiconductor. After the growth of the barrier layer, a nitrogen material and an indium material are supplied to the reactor without supply of the gallium source to perform a preflow of indium. Immediately after the preflow, a well layer is grown on the barrier layer at a second temperature while supplying an indium source and the gallium source to the reactor. The well layer comprises InGaN, and the second temperature is lower than the first temperature. The gallium source and the indium source are supplied to the reactor during plural first periods of the step of growing the well layer to grow plural InGaN layers, respectively.

Abstract: A nitride-based semiconductor light-emitting element LE1 or LD1 has: a gallium nitride substrate 11 having a principal surface 11a which makes an angle ?, in the range 40° to 50° or in the range more than 90° to 130°, with the reference plane Sc perpendicular to the reference axis Cx extending in the c axis direction; an n-type gallium nitride-based semiconductor layer 13; a second gallium nitride-based semiconductor layer 17; and a light-emitting layer 15 including a plurality of well layers of InGaN and a plurality of barrier layers 23 of a GaN-based semiconductor, wherein the direction of piezoelectric polarization of the plurality of well layers 21 is the direction from the n-type gallium nitride-based semiconductor layer 13 toward the second gallium nitride-based semiconductor layer 17.