Abstract: A nitride-based semiconductor element having excellent element characteristics is obtained by fabricating a nitride-based semiconductor layer having excellent crystallinity without performing extended etching. The nitride-based semiconductor element comprises a mask layer, having a recess portion, formed on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer, a nitride-based semiconductor layer formed on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer, and a nitride-based semiconductor element layer, formed on the nitride-based semiconductor layer, having an element region. During laterally growth, strain is relaxed thereby improving crystallinity. The underlayer is formed in a substantially flat shape, thereby avoiding extended etching.

Abstract: An electronic digital pressure switch for detecting gas pressures features improved safety. The digital pressure switch that detects gas pressures and generates outputs has a housing provided with pinholes that allow a gas to pass therethrough. With this arrangement, even if a gas should leak into the housing, the leakage gas is let out through the pinholes. Thus, when the pressure of a flammable gas is detected, it is possible to eliminate the danger of an explosion caused by the flammable gas accumulating in the housing.

Abstract: A semiconductor laser is provided which emits laser light in which the intensity center of the far-field pattern in the horizontal direction does not vary with variation of the optical output and in which the shape of the far-field pattern in the horizontal direction is stable. The width of trenches is determined so that the magnitude (E1) of the electric field at the center of a ridge and the magnitude (E2) of the electric field at the edges of the trenches provide. a ratio E1/E2 that is larger than 0.0001 and smaller than 0.01. In a semiconductor laser with a double-channel ridge structure, layers having a larger equivalent refractive index than the trenches exist outside the trenches.

Abstract: An integrated semiconductor laser device capable of improving the properties of a laser beam and reducing the cost for optical axis adjustment is provided. This integrated semiconductor laser device comprises a first semiconductor laser element including a first emission region and having either a projecting portion or a recess portion and a second semiconductor laser element including a second emission region and having either a recess portion or a projecting portion. Either the projecting portion or the recess portion of the first semiconductor laser element is fitted to either the recess portion or the projecting portion of the second semiconductor laser element.

Abstract: A high-quality keyboard device for a keyboard instrument, which can be manufactured by a simplified manufacturing process and at reduced manufacturing costs. A keyframe is formed by a molded piece of a synthetic resin. A plurality of front rail pins and a plurality of balance rail pins are arranged in a juxtaposed manner in a left-right direction at a front part and a central part of the keyframe in a front-rear direction. A plurality of keys are made of wood and each have a balance rail pin hole formed in a central portion thereof in the front-rear direction. A first reinforcing member and a second reinforcing member are made of metal and provided in the vicinity of the balance rail pins and the front rail pins for reinforcement of rigidity of the keyframe.

Abstract: A nitride semiconductor laser element capable of controlling the lateral confinement of light with a good reproducibility, the nitride semiconductor element comprising an n-type cladding layer (3), an MQW light emitting layer (4) formed on the cladding layer (3), a p-type cladding layer (5) and a p-type contact layer (6) formed on the light emitting layer (4), and an ion implantation light absorbing layer (7) formed, by introducing carbon, in regions other than a current passing region (8) in the cladding layer (5) and the contact layer (6).

Abstract: A base station controller and a mobile station to achieve high speed transmission and effective use of radio resources in a radio communications system. A communication system includes a plurality of base stations in order to provide communication among a mobile station, another mobile station and a communication link. The communication links for use in the communication are selected base on the channel quality of the communications links. The communication information is then demultiplexed for each selected link, and the data is sent parallel by way of the demultiplexed communication information along the selected communication links to allow high speed transmission.

Abstract: Improving the lifetime of an integrated semiconductor laser diode module into which a GaN semiconductor laser diode and a GaP semiconductor laser diode are integrated, and the lasing properties of the laser diodes. Prior to a joining step of an LD 1 wafer that is made of a nitride semiconductor structure formed on a GaN substrate and an LD 2 wafer that is made of an aluminum gallium indium phosphide semiconductor structure, a facet of a resonator of the nitride semiconductor structure is formed by etching A facet of a resonator of the aluminum gallium indium phosphide semiconductor structure is formed, after the joining step, by cleaving. The wafers are joined so that the facets of the resonators of the nitride semiconductor structure and aluminum gallium indium phosphide semiconductor structure are out of alignment in a lengthwise direction of the resonators.

Abstract: Provided is a manufacturing method of a nitride semiconductor device having a nitride semiconductor substrate (e.g. GaN substrate) in which dislocation concentrated regions align in stripe formation, the dislocation concentrated regions extending from a front surface to a back surface of the substrate, the manufacturing method being for stacking each of a plurality of nitride semiconductor layers on the front surface of the substrate in a constant film thickness. Grooves are formed on the nitride semiconductor substrate in the immediate areas of dislocation concentrated regions. Each of the nitride semiconductor layers is formed as a crystal growth layer on the main surface of the nitride semiconductor substrate to which the grooves have been formed.

Abstract: A blue-violet semiconductor laser device has a first p-electrode formed on its upper surface and a first n-electrode formed on its lower surface. A red semiconductor laser device has a second n-electrode formed on its upper surface and a second p-electrode formed on its lower surface. An infrared semiconductor laser device has a third n-electrode formed on its upper surface and a third p-electrode formed on its lower surface. Solder films are partially formed on the upper surface of the first p-electrode in the blue-violet semiconductor laser device. Two of the solder films are formed with a predetermined distance between them on the upper surface of the first p-electrode. This results in a portion of the first p-electrode being exposed. The first, second and third p-electrodes of the blue-violet semiconductor laser device, red semiconductor laser device, and infrared semiconductor laser device are common electrodes.

Abstract: A blue-violet semiconductor laser device has a p-electrode formed on the upper surface thereof and an n-electrode formed on the lower surface thereof. In the blue-violet semiconductor laser device, a p-n junction surface is formed where a p-type semiconductor and an n-type semiconductor are joined. A red semiconductor laser device has an n-electrode formed on the upper surface thereof and a p-electrode formed on the lower surface thereof. In the red semiconductor laser device, a p-n junction surface is formed where a p-type semiconductor and an n-type semiconductor are joined. The p-electrode of the red semiconductor laser device is bonded to the p-electrode of the blue-violet semiconductor laser device such that the red semiconductor laser device does not overlap with a blue-violet-beam-emission point of the blue-violet semiconductor laser device.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: A monolithic semiconductor laser having plural semiconductor lasers having different emission wavelengths from each other, including: a semiconductor substrate; a first double hetero-structure formed within a first area on the semiconductor substrate and having first clad layers disposed above and below a first active layer; and a second double hetero-structure formed within a second area on the semiconductor substrate and having second clad layers disposed above and below a second active layer. The first and second active layers are made of different semiconductor materials from each other. The first clad layers above and below the first active layer are of approximately the same semiconductor materials and the second clad layers above and below the second active layer are of approximately the same semiconductor materials.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: An operation detection switch capable of reproducing the manner of performance in which the speed of depressing an operating portion changes in the middle of a key action and of achieving a reduced manufacturing cost. The operation detection switch includes a switch main body and legs. A fulcrum projection, a first extending portion, protrusion and a second extending portion are provided in sequence along one end to the other end of and extending from the switch main body. Furthermore, a pressure projection is provided on the other end of the switch main body. Movable contacts corresponding to fixed contacts formed on a printed circuit board are formed at the tips of the first and the second extending portions. The operation detection switch and the printed circuit board constitute a detection device for detecting the depressing action of the key.

Abstract: A semiconductor device capable of stabilizing operations thereof is provided. This semiconductor device comprises a substrate provided with a region having concentrated dislocations at least on part of the back surface thereof, a semiconductor element layer formed on the front surface of the substrate, an insulator film formed on the region of the back surface of the substrate having concentrated dislocations and a back electrode formed to be in contact with a region of the back surface of the substrate other than the region having concentrated dislocations.

Abstract: An electronic digital pressure switch for detecting gas pressures features improved safety. The digital pressure switch that detects gas pressures and generates outputs has a housing provided with pinholes that allow a gas to pass therethrough. With this arrangement, even if a gas should leak into the housing, the leakage gas is let out through the pinholes. Thus, when the pressure of a flammable gas is detected, it is possible to eliminate the danger of an explosion caused by the flammable gas accumulating in the housing.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: A nitride-based semiconductor element having excellent element characteristics is obtained by obtaining a nitride-based semiconductor layer having excellent crystallinity without performing a long-time etching process. This nitride-based semiconductor element comprises a mask layer, having a recess portion, formed on a substantially flat upper surface of an underlayer to partially expose the upper surface of the underlayer, a nitride-based semiconductor layer formed on the exposed part of the underlayer and the mask layer while forming a void on the recess portion of the mask layer, and a nitride-based semiconductor element layer, formed on the nitride-based semiconductor layer, having an element region.