Abstract: This semiconductor laser device has the same structure as the conventional broad-area type semiconductor laser device, except that both side regions of light emission areas of active and clad layers are two-dimensional-photonic-crystallized. The two-dimensional photonic crystal formed on both side regions of the light emission area is the crystal having the property that 780 nm laser light cannot be wave-guided in a resonator direction parallel to a striped ridge within the region. The light traveling in the direction can exist only in the light emission area sandwiched between two photonic crystal regions, which results in the light laterally confined by the photonic crystal region. The optical confinement of the region suppresses the loss in the light at both edges of the stripe serving as the boundary of the optical confinement, which reduces the curve of wave surface and uniforms the light intensity distributions of NFP and FFP.

Abstract: The present invention provides a Be-based group II-VI semiconductor laser using an InP substrate and having a stacked structure capable of continuous oscillation at a room temperature. A basic structure of a semiconductor laser is constituted by using a Be-containing lattice-matched II-VI semiconductor above an InP substrate. An active laser, an optical guide layer, and a cladding layer are constituted in a double hetero structure having a type I band line-up in order to enhance the injection efficiency of carriers to the active layer. Also, the active layer, the optical guide layer, and the cladding layer, which are capable of enhancing the optical confinement to the active layer, are constituted, and the cladding layer is constituted with bulk crystals.

Abstract: A semiconductor laser having an n-cladding layer, an optical guide layer, an active layer, an optical guide layer, and a p-cladding layer above an InP substrate, in which the active layer has a layer constituted with Be-containing group II-VI compound semiconductor mixed crystals, and at least one of layers of the n-cladding layer, the optical guide layer, and the p-cladding layer has a layer constituted with elements identical with those of the Be-containing group II-VI compound semiconductor mixed crystals of the active layer, and the layer is constituted with a superlattice structure comprising, as a well layer, mixed crystals of a Be compositions with the fluctuation of the composition being within ±30% compared with the Be composition of the group II-VI compound semiconductor mixed crystals of the active layer, whereby the device characteristics of the semiconductor laser comprising the Be-containing group II-VI compound semiconductor matched with the InP substrate.

Abstract: This semiconductor laser device has the same structure as the conventional broad-area type semiconductor laser device, except that both side regions of light emission areas of active and clad layers are two-dimensional-photonic-crystallized. The two-dimensional photonic crystal formed on both side regions of the light emission area is the crystal having the property that 780 nm laser light cannot be wave-guided in a resonator direction parallel to a striped ridge within the region. The light traveling in the direction can exist only in the light emission area sandwiched between two photonic crystal regions, which results in the light laterally confined by the photonic crystal region. The optical confinement of the region suppresses the loss in the light at both edges of the stripe serving as the boundary of the optical confinement, which reduces the curve of wave surface and uniforms the light intensity distributions of NFP and FFP.

Abstract: When a semiconductor light emitting device or a semiconductor device is manufactured by growing nitride III-V compound semiconductor layers, which will form a light emitting device structure or a device structure, on a nitride III-V compound semiconductor substrate composed of a first region in form of a crystal having a first average dislocation density and a plurality of second regions having a second average dislocation density higher than the first average dislocation density and periodically aligned in the first region, device regions are defined on the nitride III-V compound semiconductor substrate such that the device regions do not substantially include second regions, emission regions or active regions of devices finally obtained do not include second regions.

Abstract: When a semiconductor light emitting device or a semiconductor device is manufactured by growing nitride III-V compound semiconductor layers, which will form a light emitting device structure or a device structure, on a nitride III-V compound semiconductor substrate composed of a first region in form of a crystal having a first average dislocation density and a plurality of second regions having a second average dislocation density higher than the first average dislocation density and periodically aligned in the first region, device regions are defined on the nitride III-V compound semiconductor substrate such that the device regions do not substantially include second regions, emission regions or active regions of devices finally obtained do not include second regions.

Abstract: When a semiconductor light emitting device or a semiconductor device is manufactured by growing nitride III–V compound semiconductor layers, which will form a light emitting device structure or a device structure, on a nitride III–V compound semiconductor substrate composed of a first region in form of a crystal having a first average dislocation density and a plurality of second regions having a second average dislocation density higher than the first average dislocation density and periodically aligned in the first region, device regions are defined on the nitride III–V compound semiconductor substrate such that the device regions do not substantially include second regions, emission regions or active regions of devices finally obtained do not include second regions.

Abstract: A laser diode capable of effectively inhibiting effects of return light is provided. A laser diode includes a substrate, and a laminated structure including a first conductive semiconductor layer, an active layer having a light emitting region, and a second conductive semiconductor layer having a projecting part on the surface thereof, on the substrate, wherein a return light inhibition part is provided on a main-emitting-side end face, and effects of return light in the vicinity of lateral boundaries of the light emitting region are inhibited by the return light inhibition part.

Abstract: When a semiconductor light emitting device or a semiconductor device is manufactured by growing nitride III-V compound semiconductor layers, which will form a light emitting device structure or a device structure, on a nitride III-V compound semiconductor substrate composed of a first region in form of a crystal having a first average dislocation density and a plurality of second regions having a second average dislocation density higher than the first average dislocation density and periodically aligned in the first region, device regions are defined on the nitride III-V compound semiconductor substrate such that the device regions do not substantially include second regions, emission regions or active regions of devices finally obtained do not include second regions.

Abstract: The present invention provides a gallium nitride semiconductor device including an electrode composed of a metallic film on an underlying gallium nitride compound semiconductor layer. The gallium nitride semiconductor device is characterized in that recessed portions are present dispersely over the whole surface area of the underlying compound semiconductor layer in contact with the electrode metallic film in such a manner that at least two recessed portions having a depth greater than the lattice constant of crystals constituting the underlying compound semiconductor layer are present on a width direction line in any 1 ?m width region of the whole surface area.

Abstract: When a semiconductor light emitting device or a semiconductor device is manufactured by growing nitride III-V compound semiconductor layers, which will form a light emitting device structure or a device structure, on a nitride III-V compound semiconductor substrate composed of a first region in form of a crystal having a first average dislocation density and a plurality of second regions having a second average dislocation density higher than the first average dislocation density and periodically aligned in the first region, device regions are defined on the nitride III-V compound semiconductor substrate such that the device regions do not substantially include second regions, emission regions or active regions of devices finally obtained do not include second regions.

Abstract: This semiconductor laser device has the same structure as the conventional broad-area type semiconductor laser device, except that both side regions of light emission areas of active and clad layers are two-dimensional-photonic-crystallized. The two-dimensional photonic crystal formed on both side regions of the light emission area is the crystal having the property that 780 nm laser light cannot be wave-guided in a resonator direction parallel to a striped ridge within the region. The light traveling in the direction can exist only in the light emission area sandwiched between two photonic crystal regions, which results in the light laterally confined by the photonic crystal region. The optical confinement of the region suppresses the loss in the light at both edges of the stripe serving as the boundary of the optical confinement, which reduces the curve of wave surface and uniforms the light intensity distributions of NFP and FFP.

Abstract: The present invention provides a gallium nitride semiconductor device including an electrode composed of a metallic film on an underlying gallium nitride compound semiconductor layer. The gallium nitride semiconductor device is characterized in that recessed portions are present dispersely over the whole surface area of the underlying compound semiconductor layer in contact with the electrode metallic film in such a manner that at least two recessed portions having a depth greater than the lattice constant of crystals constituting the underlying compound semiconductor layer are present on a width direction line in any 1 &mgr;m width region of the whole surface area.

Abstract: When making a growth mask on a substrate and using the growth mask to selectively grow nitride III-V compound semiconductors on the substrate, a multi-layered film including a nitride forming at least its top surface is used as the growth mask. The growth mask may be combination of an oxide film and a nitride film thereon, combination of a metal film and a nitride film thereon, combination of an oxide film, a film thereon made up of a nitride and an oxide, and a nitride film thereon, or combination of a first metal film, a second metal film thereon different from the first metal film and a nitride film thereon, for example. The oxide film may be a Si02, for example, the nitride film may be a TiN film or a SiN film, the film made up of a nitride and an oxide may be a SiNO film, and the metal film may be a Ti film or a Pt film, for example.

Abstract: A GaN compound semiconductor laser includes an AlGaN buried layer which buries opposite sides of a ridge stripe portion formed on a p-type AlGaN cladding layer. The AlGaN buried layer is made by first patterning an upper part of the p-type AlGaN cladding layer and a p-type GaN contact layer into a ridge stripe configuration by using a SiO2 film as an etching mask, then growing the AlGaN buried layer non-selectively on the entire substrate surface to bury both sides of the ridge stripe portion under the existence of the SiO2 film on the ridge stripe portion, and thereafter selectively removing the AlGaN buried layer from above the ridge stripe portion by etching using the SiO2 film as an etching stop layer. Thus, the GaN compound semiconductor laser is stabilized in the transverse mode, intensified in output power, and improved in lifetime.

Abstract: The present invention provides a method for growing a semiconductor layer by which the size of generable voids is controllable, inclination of the c-axis of the semiconductor crystal is avoidable and the defects in the semiconductor layer is reducible, in which a first semiconductor layer typically made of GaN is formed in a ridge pattern on a substrate, and a second semiconductor layer typically comprising GaN is then formed on the first semiconductor layer under a condition by which the growth rate in the direction parallel to the major plane of the substrate is larger than that in the direction perpendicular thereto, which is attainable by controlling the pressure in a reaction chamber in which the vapor-phase growth proceeds at 53,200 Pa (400 Torr) or above, to allow the side planes of the second semiconductor layer incline at an acute angle to the bottom plane thereof.

Abstract: When nitride series III-V group compound semiconductor is manufactured by gas phase growing using starting material for a group III element, ammonia as a starting material for a group V element and hydrogen, the gas phase molar ratio of hydrogen to the total amount of hydrogen and ammonia (H2/(H2+NH3)) is specified to 0.3<(H2/(H2+NH3))<0.7, 0.3<(H2/(H2+NH3))<0.6 or 0.4<(H2/(H2+NH3))<0.5. A nitride series III-V group compound semiconductor can thus be manufactured with less non-emission center and of excellent crystallinity.

Abstract: A GaN compound semiconductor laser includes an AlGaN buried layer which buries opposite sides of a ridge stripe portion formed on a p-type AlGaN cladding layer. The AlGaN buried layer is made by first patterning an upper part of the p-type AlGaN cladding layer and a p-type GaN contact layer into a ridge stripe configuration by using a SiO2 film as an etching mask, then growing the AlGaN buried layer non-selectively on the entire substrate surface to bury both sides of the ridge stripe portion under the existence of the SiO2 film on the ridge stripe portion, and thereafter selectively removing the AlGaN buried layer from above the ridge stripe portion by etching using the SiO2 film as an etching stop layer. Thus, the GaN compound semiconductor laser is stabilized in the transverse mode, intensified in output power, and improved in lifetime.

Abstract: A new and improved method for growing a p-type nitride III-V compound semiconductor is provided which can produce a p-type nitride compound semiconductors having a high carrier concentration, without the need for annealing to activate impurities after growth. In a preferred embodiment, a p-type nitride compound semiconductor, such as p-type GaN, is grown by metal organic chemical vapor deposition methods using a nitrogen source material which does not release hydrogen during release of nitrogen and the semiconductor is grown in an inactive gas. The nitrogen source materials may be selected from nitrogen compounds that contain hydrogen radicals and alkyl radicals and/or phenyl radicals provided that the total amount of hydrogen radicals is less than or equal to the sum total of alkyl radicals and phenyl radicals present in the nitrogen compound used as the nitrogen source material.

Abstract: A new and improved method for growing a p-type nitride III-V compound semiconductor is provided which can produce a p-type nitride compound semiconductors having a high carrier concentration, without the need for annealing to activate impurities after growth. In a preferred embodiment, a p-type nitride compound semiconductor, such as p-type GaN, is grown by metal organic chemical vapor deposition methods using a nitrogen source material which does not release hydrogen during release of nitrogen and the semiconductor is grown in an inactive gas. The nitrogen source materials may be selected from nitrogen compounds that contain hydrogen radicals groups and alkyl radicals groups and/or phenyl radicals groups provided that the total amount of hydrogen radicals groups is less than or equal to the sum total of alkyl radicals groups and phenyl radicals groups present in the nitrogen compound used as the nitrogen source material.