Abstract: A Group III nitride semiconductor laser device includes a laser structure including a support substrate with a semipolar primary surface of a hexagonal Group III nitride semiconductor, and a semiconductor region thereon, and an electrode, provided on the semiconductor region, extending in a direction of a waveguide axis in the laser device. The c-axis of the nitride semiconductor is inclined at an angle ALPHA relative to a normal axis to the semipolar surface toward the waveguide axis direction. The laser structure includes first and second fractured faces intersecting with the waveguide axis. A laser cavity of the laser device includes the first and second fractured faces extending from edges of first and second faces. The first fractured face includes a step provided at an end face of an InGaN layer of the semiconductor region and extending in a direction from one side face to the other of the laser device.

Abstract: A nitride semiconductor laser comprises a conductive support base having a primary surface of gallium nitride based semiconductor, an active layer on the primary surface, and a p-type cladding region on the primary surface. The primary surface is tilted to a reference plane perpendicular to a reference axis extending in the c-axis direction of the gallium nitride based semiconductor. The p-type cladding region comprises a first p-type group III nitride semiconductor layer of an AlGaN layer anisotropically-strained, and a second p-type group III nitride semiconductor layer of material different from the AlGaN layer. The first p-type group III nitride semiconductor layer is provided between the second p-type group III nitride semiconductor layer and the active layer. The AlGaN layer has the largest bandgap in the p-type cladding region. The second p-type group III nitride semiconductor layer has a resistivity lower than the first p-type group III nitride semiconductor layer.

Abstract: A group-III nitride semiconductor laser device comprises: a laser structure including a semiconductor region and a support base having a semipolar primary surface of group-III nitride semiconductor; a first reflective layer, provided on a first facet of the region, for a lasing cavity of the laser device; and a second reflective layer, provided on a second facet of the region, for the lasing cavity. The laser structure includes a laser waveguide extending along the semipolar surface. A c+ axis vector indicating a <0001> axial direction of the base tilts toward an m-axis of the group-III nitride semiconductor at an angle of not less than 63 degrees and less than 80 degrees with respect to a vector indicating a direction of an axis normal to the semipolar surface. The first reflective layer has a reflectance of less than 60% in a wavelength range of 525 to 545 nm.

Abstract: A laser diode device includes: a semiconductor substrate including a semi-polar surface, the semiconductor substrate being formed of a hexagonal III-nitride semiconductor; an epitaxial layer including a light emitting layer, the epitaxial layer being formed on the semi-polar surface of the semiconductor substrate, and the epitaxial layer including a ridge section; a first electrode formed on a top surface of the ridge section; an insulating layer covering the epitaxial layer in an adjacent region of the ridge section and a side surface of the ridge section, the insulating layer covering part or all of side surfaces of the first electrode continuously from the epitaxial layer; a pad electrode formed to cover a top surface of the first electrode and the insulating layer, the pad electrode being electrically connected to the first electrode; and a second electrode formed on a surface, of the semiconductor substrate, opposite to the semi-polar surface.

Abstract: A method for manufacturing a light-emitting diode, which includes the steps of: providing a substrate having a plurality of protruded portions on one main surface thereof wherein the protruded portion is made of a material different in type from that of the substrate and growing a first nitride-based III-V Group compound semiconductor layer on each recess portion of the substrate through a state of making a triangle in section wherein a bottom surface of the recess portion becomes a base of the triangle; laterally growing a second nitride-based III-V Group compound semiconductor layer on the substrate from the first nitride-based III-V Group compound semiconductor layer; and successively growing, on the second nitride-based III-V Group compound semiconductor layer, a third nitride-based III-V Group compound semiconductor layer of a first conduction type, an active layer, and a fourth nitride-based III-V compound semiconductor layer of a second conduction type.

Abstract: A nitride semiconductor light-emitting device has a semiconductor ridge, and includes a first inner-layer between an active layer and an n-type cladding and a second inner-semiconductor layer between the active layer and a p-type cladding. The first inner-layer, active layer and second inner-layer constitute a core-region. The n-type cladding, core-region and p-type cladding constitute a waveguide-structure. The active layer and the first inner-layer constitute a first heterojunction inclined at an angle greater than zero with respect to a reference plane of the c-plane of the nitride semiconductor of the n-type cladding. Piezoelectric polarization of the well layer is oriented in a direction from the p-type cladding toward the n-type cladding. The second inner-layer and InGaN well layer constitute a second heterojunction. A distance between the ridge bottom and the second heterojunction is 200 nm or less. The ridge includes a third heterojunction between the second inner-layer and the p-type cladding.

Abstract: A nitride semiconductor laser includes an electrically conductive support substrate with a primary surface of a gallium nitride based semiconductor, an active layer provided above the primary surface, and a p-type cladding region provided above the primary surface. The primary surface is inclined relative to a reference plane perpendicular to a reference axis extending in a direction of the c-axis of the gallium nitride based semiconductor. The p-type cladding region includes first and second p-type Group III nitride semiconductor layers. The first p-type semiconductor layer comprises an InAlGaN layer including built-in anisotropic strain. The second p-type semiconductor layer comprises semiconductor different from material of the InAlGaN layer. The first nitride semiconductor layer is provided between the second p-type semiconductor layer and the active layer. The second p-type semiconductor layer has a resistivity lower than that of the first p-type semiconductor layer.

Abstract: A group-III nitride semiconductor laser device comprises: a laser structure including a semiconductor region and a support base having a semipolar primary surface of group-III nitride semiconductor; a first reflective layer, provided on a first facet of the region, for a lasing cavity of the laser device; and a second reflective layer, provided on a second facet of the region, for the lasing cavity. The laser structure includes a laser waveguide extending along the semipolar surface. A c+ axis vector indicating a <0001> axial direction of the base tilts toward an m-axis of the group-III nitride semiconductor at an angle of not less than 63 degrees and less than 80 degrees with respect to a vector indicating a direction of an axis normal to the semipolar surface. The first reflective layer has a reflectance of less than 60% in a wavelength range of 525 to 545 nm.

Abstract: A semiconductor device comprising a substrate made of a material with a hexagonal crystal structure and having a substrate axis which is perpendicular to a principal surface of the substrate; and a nitride-based group III-V compound semiconductor layer grown directly on and in contact with the principal surface of the substrate without growing a buffer layer between the substrate and the nitride-based group III-V compound semiconductor layer, wherein, a direction of a growth axis of the semiconductor layer is substantially the same as a direction of the substrate axis of the substrate.

Abstract: A gallium nitride-based semiconductor laser device with reduced threshold current. The gallium nitride-based semiconductor laser device is provided with an n-type cladding layer, an n-side light guide layer, an active layer, a p-side light guide layer, and a p-type cladding layer. The n-side light guide layer and the p-side light guide layer both contain indium. Each of indium compositions of the n-side light guide layer and the p-side light guide layer is not less than 2% and not more than 6%. A film thickness of the n-type cladding layer is in the range of not less than 65% and not more than 85% of a total of the film thickness of the n-type cladding layer and a film thickness of the p-type cladding layer.

Abstract: In a method for manufacturing a semiconductor device, the method includes the step of growing a nitride-based III-V compound semiconductor layer, which forms a device structure, directly on a substrate without growing a buffer layer, the substrate being made of a material with a hexagonal crystal structure and having a principal surface that is oriented off at an angle of not less than ?0.5° and not more than 0° from an R-plane with respect to a direction of a C-axis.

Abstract: A group III nitride semiconductor laser device includes a laser structure, an insulating layer, an electrode and dielectric multilayers. The laser structure includes a semiconductor region on a semi-polar primary surface of a hexagonal group III nitride semiconductor support base. The dielectric multilayers are on first and second end-faces for the laser cavity. The c-axis of the group III nitride tilts by an angle ALPHA from the normal axis of the primary surface in the waveguide axis direction from the first end-face to the second end-faces. A pad electrode has first to third portions provided on the first to third regions of the semiconductor regions, respectively. An ohmic electrode is in contact with the third region through an opening of the insulating layer. The first portion has a first arm, which extends to the first end-face edge. The third portion is away from the first end-face edge.

Abstract: A group-III nitride semiconductor device includes a light emitting layer emitting light of a wavelength in the range of 480 to 600 nm; a first contact layer over the light emitting layer; a second contact layer in direct contact with the first contact layer; and a metal electrode in direct contact with the second contact layer. The first and second contact layers comprise a p-type gallium nitride-based semiconductor. The p-type dopant concentration of the first contact layer is lower than that of the second contact layer. The light emitting layer comprises a gallium nitride-based semiconductor. The interface between the first and second contact layers tilts at an angle of not less than 50 degrees and smaller than 130 degrees from a plane orthogonal to a reference axis extending along the c-axis. The second contact layer has a thickness within the range of 1 to 50 nm.

Abstract: A gallium nitride-based semiconductor laser device with reduced threshold current. The gallium nitride-based semiconductor laser device is provided with an n-type cladding layer, an n-side light guide layer, an active layer, a p-side light guide layer, and a p-type cladding layer. The n-side light guide layer and the p-side light guide layer both contain indium. Each of indium compositions of the n-side light guide layer and the p-side light guide layer is not less than 2% and not more than 6%. A film thickness of the n-type cladding layer is in the range of not less than 65% and not more than 85% of a total of the film thickness of the n-type cladding layer and a film thickness of the p-type cladding layer 23.

Abstract: A nitride semiconductor laser device includes a p-type cladding layer, an active layer and an n-type cladding layer. The p-type cladding layer and the n-type cladding layer comprise indium and aluminum as group-III constituent. The n-type cladding layer, active layer and p-type cladding layer are arranged along the normal of a semi-polar semiconductor surface of a substrate. This surface tilts toward the m-axis of the hexagonal nitride by an angle of 63 degrees or more and smaller than 80 degrees from a plane orthogonal to a reference axis extending along the c-axis thereof. The active layer generates light having a peak wavelength in the range of 480 to 600 nm. The refractive indices of the n-type cladding layer and p-type cladding layer are smaller than that of GaN. The n-type cladding layer has a thickness of 2 ?m or more while the p-type cladding layer has a thickness of 500 nm or more.

Abstract: A Group III nitride semiconductor laser device includes a laser structure including a support substrate with a semipolar primary surface of a hexagonal Group III nitride semiconductor, and a semiconductor region thereon, and an electrode, provided on the semiconductor region, extending in a direction of a waveguide axis in the laser device. The c-axis of the nitride semiconductor is inclined at an angle ALPHA relative to a normal axis to the semipolar surface toward the waveguide axis direction. The laser structure includes first and second fractured faces intersecting with the waveguide axis. A laser cavity of the laser device includes the first and second fractured faces extending from edges of first and second faces. The first fractured face includes a step provided at an end face of an InGaN layer of the semiconductor region and extending in a direction from one side face to the other of the laser device.

Abstract: A nitride semiconductor laser includes an electrically conductive support substrate with a primary surface of a gallium nitride based semiconductor, an active layer provided above the primary surface, and a p-type cladding region provided above the primary surface. The primary surface is inclined relative to a reference plane perpendicular to a reference axis extending in a direction of the c-axis of the gallium nitride based semiconductor. The p-type cladding region includes first and second p-type Group III nitride semiconductor layers. The first p-type semiconductor layer comprises an InAlGaN layer including built-in anisotropic strain. The second p-type semiconductor layer comprises semiconductor different from material of the InAlGaN layer. The first nitride semiconductor layer is provided between the second p-type semiconductor layer and the active layer. The second p-type semiconductor layer has a resistivity lower than that of the first p-type semiconductor layer.

Abstract: A method for manufacturing a light-emitting diode, which includes the steps of: providing a substrate having a plurality of protruded portions on one main surface thereof wherein the protruded portion is made of a material different in type from that of the substrate and growing a first nitride-based III-V Group compound semiconductor layer on each recess portion of the substrate through a state of making a triangle in section wherein a bottom surface of the recess portion becomes a base of the triangle; laterally growing a second nitride-based III-V Group compound semiconductor layer on the substrate from the first nitride-based III-V Group compound semiconductor layer; and successively growing, on the second nitride-based III-V Group compound semiconductor layer, a third nitride-based III-V Group compound semiconductor layer of a first conduction type, an active layer, and a fourth nitride-based III-V compound semiconductor layer of a second conduction type.

Abstract: A laser diode includes: a substrate; a semiconductor layer including a lower cladding layer, an active layer, and an upper cladding layer; a strip-shaped ridge provided on an upper cladding layer side in the semiconductor layer; and a pair of resonator end faces sandwiching the semiconductor layer and the ridge. The substrate includes strip-shaped grooves provided on both sides of a portion facing the ridge along the portion facing the ridge, and extending in a direction different from a direction orthogonal to the extending direction of the ridge, and L1, L2, and L3 satisfy the following relationship, L1<L3/2 L2?L3/3 where L1 is a length of each groove, L2 is a length of a groove non-form rectangular region in the extending direction of the ridge, the groove non-form rectangular region being sandwiched by the grooves from the extending direction of the ridge, and L3 is a resonator length.

Abstract: In a method for manufacturing a semiconductor device, the method includes the step of growing a nitride-based III-V compound semiconductor layer, which forms a device structure, directly on a substrate without growing a buffer layer, the substrate being made of a material with a hexagonal crystal structure and having a principal surface that is oriented off at an angle of not less than ?0.5° and not more than 0° from an R-plane with respect to a direction of a C-axis.