摘要:
Monitoring and control apparatus for fail-safe monitoring for normal operation of traffic signal lights provided at an intersection or the like where a plurality of roads intersect. The illumination conditions of respective signal lights are detected using as sensor device, and when the number of illuminated or non-illuminated signal lights is a predetermined number, a normal judgment output of logic value 1 corresponding to a high energy condition is generated while, when the number of illuminated or non-illuminated signal lights is not the predetermined number, an abnormal judgment output of logic value 0 corresponding to a low energy condition is generated. As a result, when a fault in the monitoring apparatus stops the output, the resultant output condition is the same as for a danger condition due to a signal light abnormality, resulting in an extremely safe signal light monitoring and control with excellent fail-safe characteristics.
摘要:
A gallium nitride-based compound semiconductor laser has a double-heterojunction structure, in which an active layer is sandwiched between cladding layers, on a sapphire substrate. A GaN current blocking layer having a striped opening portion is formed on the p-cladding layer. A p-GaN buried layer and a contact layer through which a current is injected into the opening portion of the current blocking layer and which are larger in area than the opening portion are formed. The active layer has a multiple quantum well structure constituted by a cyclic structure formed by cyclically stacking two types of InGaAlN layers which have different band gaps and are 10 nm or more thick.
摘要:
A top surface of a wafer, at which semiconductor devices are formed, is bonded to an auxiliary plate by means of a first wax. In a state where the auxiliary plate is bonded to a polishing jig by means of a second wax, a bottom surface of the wafer, at which a sapphire substrate is provided, is polished. The second wax is melted and the auxiliary plate is removed from the polishing jig. In this state, scribe lines are formed in the bottom surface of the wafer according to a device separation pattern. Then, the bottom surface of the wafer is attached to an adhesive sheet, following which the first wax is melted and the wafer is removed from the auxiliary plate 105. Subsequently, the adhesive sheet is extended and the wafer is divided into the devices along the scribe lines.
摘要:
A semiconductor light-emitting device comprises a semiconductor light-emitting device section of a hexagonal type; and an electrically conductive semiconductor substrate of a cubic type combined into the semiconductor light-emitting device, and having an orientation of its cleavage facet conformed to an orientation of the cleavage facet of one of semiconductor layers forming the semiconductor light-emitting device section. The substrate of the cubic type is cleaved so that the semiconductor light-emitting device section of the hexagonal type is induced to be cleaved, and that a mirror surface can be easily formed.
摘要:
A semiconductor laser exhibiting an oscillation wavelength of 450 nm or less and comprising a substrate, a lower clad layer formed on or above the substrate and mainly composed of a III-V Group compound semiconductor, an active layer formed directly on the lower clad layer and mainly composed of a III-V Group compound semiconductor, and an upper p-type clad layer formed directly on the active layer and mainly composed of a III-V Group compound semiconductor. This semiconductor laser is characterized in that the upper p-type clad layer contains Mg, Si and at least one impurities for compensating residual donors.
摘要:
AlN is added to a SiC light emitting layer of an optical semiconductor device in a molecular state, and an association of AlN is formed between crystal lattice points, which are close to each other in said light emitting layer. Said association is largely different from said SiC in degree of electron negativity so that said association traps a carrier in said light emitting layer, and forms an exciton.