Abstract: A method of reducing the reverse recovery charge of thyristors without substantially increasing forward voltage drop by first determining the depth of the anode PN junction from a major surface adjoining a cathode emitter region. The depth of maximum defect generation in thyristor on irradiation through the major surface with a given radiation source radiating particles with molecular weight greater than one, preferably proton or alpha particles, and adjusting the energy level at the major surface of the thyristor from the radiation source to provide the depth of maximum defect generation adjacent the anode PN junction and preferably in the anode base region within 20 micrometers of the anode PN junction or in the anode emitter region within 15 micrometers of the anode PN junction.

Abstract: A light activated silicon switch (LASS) is disclosed in which light is transmitted from a light trigger source to target areas prepared in the cathode-base and anode-emitter regions of the silicon wafer. These target areas are V-shaped channels etched in the silicon wafer. Light transmitting conduits, each consisting of a central core of light transmissive material, with an outer cladding, are arranged to transmit the light energy to the respective target areas. The cladding is removed at one end of each conduit for optically coupling the light to the proximate target area, while the other end of the conduit is adapted to receive a light trigger signal of appropriate wave length.

Abstract: A four-layer semiconductor thyristor including a planar recombination region extending on both sides of a planar cathode-emitter junction.

Abstract: Irradiated regions are formed in materials such as semiconductor bodies by nuclear radiation where the irradiated regions are of a desired thickness, dosage and dosage gradient, a desired distance from a selected surface of the material. A nuclear radiation beam from a given radiation source radiating particles with molecular weight of at least one (1) is provided that can penetrate the material through a selected surface to a depth greater than the maximum depth of the irradiated region from the selected surface. A beam modifier is formed of a given material and non-uniform shape to modify the energy of the radiation beam on transmission therethrough to form a transmitted radiation beam capable of forming an irradiated region of a desired thickness and dosage gradient in the material a given distance from the selected surface on irradiation of the material through the selected surface with the transmitted radiation beam.

Abstract: A method for making a pnpn semiconductor reverse conducting thyristor comprises the steps of forming n-type semiconductor layers on both sides of a p-type semiconductor substrate for forming an n-type emitter layer and an n-type anode-base layer. A p-type semiconductor impurity region is formed in the n-type anode-base layer for forming a p-type anode layer. A p.sup.+ -type semiconductor layer is ion implanted in the p-type substrate adjacent to the n-type cathode emitter layer by irradiating it with boron atoms.

Abstract: This invention relates to a thyristor and more particularly to improvements to increase the withstand voltage and increase the control speed of a thyristor.

Abstract: A photo-transistor includes a multi-apertured collector electrode disposed on a semiconductor collector layer. A laser diode and a light pipe are provided for each aperture such that the light from the laser is transmitted to its associated aperture via the light pipe. Means are included for sequentially pulsing each laser so as to cause a high-frequency intermittent current in the photo-transistor piece of molybdenum 88 which provides improved current flow and heat sinking for the transistor 10.

Abstract: A method for doping a wafer of n-type seimiconductor material having two surfaces includes the steps of applying a boron solution to a first surface of the wafer and heating the wafer to drive the boron into the semiconductor wafer for forming a first p-type region. Both surfaces of the wafer are then exposed to a gallium vapor for forming a second p-type region on the second surface and deepening the extent of the first p-type region.

Abstract: A semiconductor device such as a film or hybrid integrated circuit is provided having a relatively lightly doped, epitaxially grown silicon layer with a relatively long minority carrier lifetime. The lightly doped silicon layer of less than about 1.times.10.sup.17 per cm.sup.3 is grown on a heavily doped silicon layer of greater than about 1.times.10.sup.19 and preferably greater than about 1.times.10.sup.20 per cm.sup.3 formed with phosphorus or boron impurity. The heavily doped silicon layer is preferably formed, either in a semiconductor body or an epitaxial layer on an insulator substrate, preferably by diffusing the impurity into the body or epitaxial layer. Preferably, the semiconductor device is a thin-film device and most desirably a silicon-on-sapphire device.

Abstract: The switching time of certain semiconductor devices is decreased while maintaining other electrical characteristics of the devices by irradiating them with a neutron radiation source of greater than 1.0 Mev. to a dosage between 1.times.10.sup.11 and 1.times.10.sup.15 neutrons per square centimeter. The irradiation is preferably to a dosage between 1.times.10.sup.1 and 1.times.10.sup.14 neutrons per square centimeter and preferably has substantial energy greater than 14 Mev. The devices are also annealed during and/or subsequent to the irradiation at a temperature higher than the highest specified temperature and preferably at least 50.degree. C. higher than the highest specified temperature.

Abstract: An integrated amplifying gate thyristor is provided with an integral diode in the thyristor structure in the same semiconductor body. The diode provides gate assist turn-off capability with the same gate electrode used to turn-on a pilot thyristor of the device. The common cathode-base region of the pilot and main thyristors also is common with the anode region of the diode. The current gain of the NPN transistor structure formed at the diode and the common anode-base region at the diode is less than the ratio of I.sub.FB /I.sub.g, where I.sub.FB is the forward anode current on triggering the main thyristor into the low impedance conduction state by applying a threshold negative gate assist current (I.sub.G) and an operating anode-cathode load potential, and I.sub.g is a negative gate current selected to assist in turn-off of the main thyristor.

Abstract: Conductivity modulation states in a first component of a power integrated circuit are dynamically isolated from a second component of the integrated circuit having at least one common active region with the first component by selective irradiation of portions of the common regions between the components. Preferably the irradiation is accomplished by masking the component portions of the body with a radiation shield and irradiating selected portions of the common active regions between the component portions with a suitable radiation source. The radiation source is preferably an electron beam of an energy level between about 1 and 3 Mev, preferably where the irradiation is carried to a dosage between 1.times.10.sup.13 and 1.times.10.sup.15 e/cm.sup.2 and most desirably between 4.times.10.sup.13 and 2.times.10.sup.14 e/cm.sup.2. New high speed bilateral thyristors, reverse switching rectifiers and reverse conducting thyristors are also provided.

Abstract: Solid layer semiconductor compositions are deposited by the simultaneous sputtering from a sputter target and electrically discharge a reacting gas preferably by application of an RF potential. Preferably, the method is used to make solid solution layers and most desirably solid solution epitaxial layers of at least two semiconductor materials. The method may be used to make novel metastable compositions such as (GaAs).sub.1-x Si.sub.x, (GaAs).sub.1-x, Ge.sub.x, (InSb).sub.1-x Si.sub.x, (InSb).sub.1-x Ge.sub.x, (InAs).sub.1-x Si.sub.x and (InAs).sub.1-x Ge.sub.x (where x is a number greater than about 0.01, and x+(1-x)=1, and Ga.sub.x As.sub.y Si.sub.z, Ga.sub.x As.sub.y Ge.sub.z, In.sub.x Sb.sub.y Si.sub.z, In.sub.x Sb.sub.y Ge.sub.z, In.sub.x As.sub.y Si.sub.z, In.sub.x As.sub.y Ge.sub.z and In.sub.x Sb.sub.y As.sub.z (where x, y and z are numbers greater than about 0.01, and x+y+z=1).

Abstract: A light activated silicon switch (LASS) is disclosed in which light is transmitted from a light trigger source to appropriate target areas on the body of the silicon wafer. The optical conduits for transmitting the light, such as optical fibers, are underlaid with a metallic coating for establishing electrical contact to the silicon wafer, and are arranged on the surface of the silicon wafer, in a pattern so as to afford the least impediment to thermal conduction. The target areas are spread over the active areas of the silicon wafer so as to approximate uniform turn-on. In the preferred arrangement, the optical channels are arranged radially on the substantially circular silicon wafer, in cooperation with symmetrically placed target spots.

Abstract: A thyristor having an auxiliary cathode emitter region disposed in the central portion of the device in PN junction relationship with a cathode base region is disclosed. An extra impurity region of the same conductivity type as the cathode base region is disposed in the cathode base region in the central portion of the device inwardly of the outer boundary of the auxiliary cathode emitter. The extra impurity region has a higher impurity density gradient adjacent the common PN junction formed by the cathode and anode base regions than the remainder of such junction.

Abstract: This disclosure sets forth a method of manufacturing a gate turn-off (GTO) thyristor which includes the step of altering the lateral electrical resistance of one base region by out diffusion from selected portions of the base region.

Abstract: The present invention concerns a power diode with a semiconductor body having an inner zone with a given thickness and a given specific resistance, and having on each side of said inner zone at least one outer zone which adjoins the inner zone and has a lower specific resistance in comparison with the inner zone. The diode is characterized in that the specific resistance and the thickness of the inner zone are so adapted to each other that U.sub.B < U.sub..rho.T, wherein U.sub.B is the avalanche voltage, and U.sub..rho.T is the voltage at which the space-charge zone includes the entire relatively lightly doped inner zone.

Abstract: A solar cell is comprised of (1) a Cu.sub.2 S thin film evaporated on a conductive substrate at an elevated temperature thereby growing a polycrystalline film of preferred orientation, and (2) an outer CdS layer grown epitaxially on the Cu.sub.2 S film.

Abstract: The present invention is directed to a thyristor having a configuration for educing turn-off time, said thyristor comprises a main thyristor portion having a main emitter electrode and a control electrode and an auxiliary thyristor portion having an auxiliary emitter electrode and adapted for amplifying the control current, the arrangement includes a voltage source connected to the auxiliary thyristor, and supplying the auxiliary emitter electrode with a current the direction of which is opposite to the direction of the control current.BACKGROUND OF THE INVENTION1. Field of the InventionThis invention is in the field of discrete semiconductor devices and is particularly directed to discrete thyristors.2. Description of the Prior ArtThe "turn-off time" of a thyristor is the time between the zero passage of a load current and the moment when the thyristor has regained its blocking capability.It is known that the turn-off time of a thyristor can be decreased considerably by provision of recombination centers.

Abstract: The present invention is directed to a semiconductor device comprising a body of semiconductor material having at least one p-n junction therein. The body of semiconductor material has opposed, flat, substantially parallel main faces and an edge portion extending between the two main faces. The p-n junction is exposed at the edge portion of the body. Metal electrodes are affixed to at least a portion of the two faces of the body of semiconductor material. A layer of protective material covers the edge portion, the metal electrodes, and any exposed portions of the two main faces of the body. Electrical contacts made to the body of semiconductor material by lead electrodes in compression bonded contact with the metal electrodes and in some cases with at least a portion of the main faces of the body of semiconductor material. The surface of the lead electrodes in contact with the metal electrodes and in some instances the main faces of the semiconductor body is comprised of a plurality of lands and grooves.