Abstract: There are provided a semiconductor device in which a drain leak current can be reduced in the transistor operation while high vertical breakdown voltage is achieved and a method for producing the semiconductor device. In the semiconductor device, an opening 28 that extends from an n+-type contact layer 8 and reaches an n-type drift layer 4 through a p-type barrier layer 6 is formed. The semiconductor device includes a regrown layer 27 located so as to cover portions of the p-type barrier layer 6 and the like that are exposed to the opening, the regrown layer 27 including an undoped GaN channel layer 22 and a carrier supply layer 26; an insulating layer 9 located so as to cover the regrown layer 27; and a gate electrode G located on the insulating layer 9. In the p-type barrier layer, the Mg concentration A (cm?3)and the hydrogen concentration B (cm?3) satisfy 0.1<B/A<0.9 . . . (1).

Abstract: A vertical semiconductor device in which pinch-off characteristics and breakdown voltage characteristics can be stably improved by fixing the electric potential of a p-type GaN barrier layer with certainty is provided. The semiconductor device includes a GaN-based stacked layer having an opening, a regrown layer including a channel located so as to cover a wall surface of the opening, an n+-type source layer that is in ohmic contact with the source electrode, a p-type GaN barrier layer, and a p+-type GaN-based supplementary layer located between the p-type GaN barrier layer and the n+-type source layer. The p+-type GaN-based supplementary layer and the n+-type source layer form a tunnel junction to fix the electric potential of the p-type GaN barrier layer at a source potential.

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 method of fabricating a single crystal gallium nitride substrate the step of cutting an ingot of single crystal gallium nitride along predetermined planes to make one or more single crystal gallium nitride substrates. The ingot of single crystal gallium nitride is grown by vapor phase epitaxy in a direction of a predetermined axis. Each predetermined plane is inclined to the predetermined axis. Each substrate has a mirror polished primary surface. The primary surface has a first area and a second area. The first area is between an edge of the substrate and a line 3 millimeter away from the edge. The first area surrounds the second area. An axis perpendicular to the primary surface forms an off-angle with c-axis of the substrate. The off-angle takes a minimum value at a first position in the first area of the primary surface.

Abstract: Oxygen can be doped into a gallium nitride crystal by preparing a non-C-plane gallium nitride seed crystal, supplying material gases including gallium, nitrogen and oxygen to the non-C-plane gallium nitride seed crystal, growing a non-C-plane gallium nitride crystal on the non-C-plane gallium nitride seed crystal and allowing oxygen to infiltrating via a non-C-plane surface to the growing gallium nitride crystal. Oxygen-doped {20-21}, {1-101}, {1-100}, {11-20} or {20-22} surface n-type gallium nitride crystals are obtained.

Abstract: A III-nitride semiconductor laser device including: a laser structure including a support base and a semiconductor region, the support base including a hexagonal III-nitride semiconductor and having a semipolar primary surface, and the semiconductor region being provided on the semipolar primary surface of the support base; and an electrode provided on the semiconductor region of the laser structure, the semiconductor region including a first cladding layer, a second cladding layer, and an active layer.

Abstract: A group III nitride semiconductor optical device 11a has a group III nitride semiconductor substrate 13 having a main surface 13a forming a finite angle with a reference plane Sc orthogonal to a reference axis Cx extending in a c-axis direction of the group III nitride semiconductor and an active layer 17 of a quantum-well structure, disposed on the main surface 13a of the group III nitride semiconductor substrate 13, including a well layer 28 made of a group III nitride semiconductor and a plurality of barrier layers 29 made of a group III nitride semiconductor. The main surface 13a exhibits semipolarity. The active layer 17 has an oxygen content of at least 1×1017 cm?3 but not exceeding 8×1017 cm?3. The plurality of barrier layers 29 contain an n-type impurity other than oxygen by at least 1×1017 cm?3 but not exceeding 1×1019 cm?3 in an upper near-interface area 29u in contact with a lower interface 28Sd of the well layer 28 on the group III nitride semiconductor substrate side.

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: Affords MOCVD reactors with which, while deposited films are uniformized in thickness, film deposition efficiency can be improved. An MOCVD reactor (1) is furnished with a susceptor (5) and a duct (11). The susceptor (5) has a carrying surface for heating and carrying substrates (20). The duct (11) is for conducting reaction gas (G) to the substrates (20). The susceptor (5) is rotatable with the carrying surface fronting on the duct (11) interior. The duct (11) has channels (11b) and (11c), which merge on the duct end upstream of Point A4. The height of the duct (11) running along the reaction gas (G) flow direction monotonically diminishes heading toward the duct downstream end from Point P1 to Point P2, stays constant from Point P2 to Point P3, and monotonically diminishes heading downstream from Point P3. Point P1 lies upstream of Point A4, while Point P3 lies on the susceptor (5).

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: Metal organic chemical vapor deposition equipment is metal organic chemical vapor deposition equipment for forming a film on a substrate by using a reactant gas, and includes a susceptor heating the substrate and having a holding surface for holding the substrate, and a flow channel for introducing the reactant gas to the substrate. The susceptor is rotatable with the holding surface kept facing an inner portion of the flow channel, and a height of the flow channel along a flow direction of the reactant gas is kept constant from a position to a position, and is monotonically decreased from the position to the downstream side. It is thereby possible to improve film formation efficiency while allowing the formed film to have a uniform thickness.

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 includes a supporting substrate, a conductive layer placed on the supporting substrate, and at least one group III nitride semiconductor layer placed on the conductive layer. Of the group III nitride semiconductor layers, a conductive-layer-neighboring group III nitride semiconductor layer has n type conductivity, dislocation density of at most 1×107 cm?2, and oxygen concentration of at most 5×1018 cm?3. Thus, an n-down type device having a semiconductor layer of high crystallinity can be provided.

Abstract: An intake control system for an internal combustion engine is capable of ensuring a differential pressure across an EGR valve, and controlling an EGR amount with high accuracy. A target fresh air amount is set based on a demanded torque calculated according to operating conditions of the engine. A differential pressure across an EGR valve is set as a target differential pressure. When it is determined that the across-valve differential pressure is not in a state in which the target differential pressure can be ensured, an opening degree of the EGR valve is controlled to limit an EGR amount. An opening degree of a throttle valve is controlled based on the target fresh air amount, so as to ensure the target differential pressure.

Abstract: A group III nitride semiconductor light-emitting device comprises an n-type gallium nitride-based semiconductor layer, a first p-type AlXGa1-XN (0?X<1) layer, an active layer including an InGaN layer, a second p-type AlYGa1-YN (0?Y?X<1) layer, a third p-type AlZGa1-XN layer (0?Z?Y?X<1), and a p-electrode in contact with the third p-type AlZGa1-ZN layer. The active layer is provided between the n-type gallium nitride-based semiconductor layer and the first p-type AlXGa1-XN layer. The second p-type AlYGa1-YN (0?Y?X<1) layer is provided on the first p-type AlXGa1-XN layer. The p-type dopant concentration of the second p-type AlYGa1-YN layer is greater than the p-type dopant concentration of the first p-type AlXGa1-XN layer. The third p-type AlZGa1-ZN layer (0?Z?Y?X<1) is provided on the second p-type AlYGa1-YN layer. The p-type dopant concentration of the second p-type AlYGa1-YN layer is greater than a p-type dopant concentration of the third p-type AlZGa1-ZN layer.

Abstract: A method of forming a p-type gallium nitride based semiconductor without activation annealing is provided, and the method can provide a gallium nitride based semiconductor doped with a p-type dopant. A GaN semiconductor region 17 containing a p-type dopant is formed on a supporting base 13 in a reactor 10. An organometallic source and ammonia are supplied to the reactor 10 to grow the GaN semiconductor layer 17 on a GaN semiconductor layer 15. The GaN semiconductor is doped with a p-type dopant. Examples of the p-type dopant include magnesium. After the GaN semiconductor regions 15 and 17 are grown, an atmosphere 19 containing at least one of monomethylamine and monoethylamine is prepared in the reactor 10. After the atmosphere 19 is prepared, a substrate temperature is decreased from the growth temperature of the GaN semiconductor region 17. When the substrate temperature is lowered to room temperature after this film formation, a p-type GaN semiconductor 17a and an epitaxial wafer E has been fabricated.

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.

Abstract: Provided is a nitride electronic device having a structure that allows the reduction of leakage by preventing the carrier concentration from increasing in a channel layer. An inclined surface and a primary surface of a semiconductor stack extend along first and second reference planes R1, R2, respectively. The primary surface of the stack is inclined at an angle ranging from 5 to 40 degrees with respect to a reference axis indicating a c-axis direction of hexagonal group III nitride. An axis normal to the plane R1 and the axis form an angle smaller than the angle an axis normal to the plane R2 and the axis form. The oxygen concentration of the channel layer is lower than 1×1017 cm?3. It becomes possible to avoid increase in carrier concentration of the channel layer caused by the oxygen addition, thereby reducing leakage current via the channel layer in the transistor.

Abstract: A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate having a hexagonal III-nitride semiconductor and having a semipolar primary surface; forming a substrate product having a laser structure, an anode electrode and a cathode electrode, the laser structure including a substrate and a semiconductor region 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 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: Disclosed herein is a suspension arm component for vehicles with sufficient strength or rigidity to withstand repetitive compressive and tensile forces, and a method for manufacturing such a component by pressing or hemming process alone, without recourse to any welding process, forming quickly and simply, a process with advantages in terms of material yield and cost. The suspension arm component for vehicles includes first flange pieces as well as second flange pieces, and a pair of half members, each having a hat-like shaped cross-section perpendicular to its axis, are joined together to protrude the first flange part and the second flange part from an expanded part, where both the first flange part and the second flange part extend linearly along the axis of the main body part. The main body part presents a rectangular shape in its side view.