Abstract: An improved unijunction transistor having increased valley current is characterized by a region of locally lower lifetime proximate the emitter-base junction. The lifetime is reduced either by overall irradiation of the device or, more preferably, by selective irradiation of the junction area alone.

Abstract: High speed semiconductor rectifiers are fabricated by providing a rectifier, increasing the temperature thereof to a relatively high value, irradiating the rectifier with high energy lattice-damage causing particles while maintaining the relatively high temperature, and annealing the irradiated rectifier at a temperature and for a time sufficient to decrease the leakage current of the rectifier to a low value without substantially increasing the reverse recovery time of the rectifier.

Abstract: The dv/dt characteristics of a bidirectional thyristor are improved by irradiating selected portions of the device with high energy crystal lattice-damaging particles. In an exemplary embodiment, the commutating dv/dt of a triac is enhanced by the masked, selective irradiation of the boundaries between conducting portions and between the gate and the conducting portions.

Abstract: Disclosed is a double side cooled, pressure mounted semiconductor package and a method for the manufacture thereof. The package is formed by directly bonding upper and lower metal contact assemblies to an annular ceramic housing. Assembly is simplified if at least one contact assembly comprises two parts applied sequentially. An annular flange having a central opening approximately the size of the central opening in the annular housing and having an outside diameter larger than the outside diameter of the ceramic housing is direct bonded to one end of the housing simultaneously with a lower semiconductor contact. After a conventional semiconductor pellet is positioned in the housing, the second part, a metal contact disc with an outside diameter approximately equaling the outside diameter of the flange, is positioned thereover. Finally, the flange and the disc are welded around their peripheries.

Abstract: Disclosed is a semiconductor body mounted on an electrically-insulative, thermally-conductive plate which also carries metallized contacts electrically connected to the various contact areas associated with the semiconductor body. A protective one-piece insulative bridge overlies the semiconductor body and includes legs secured to the plate and a cross member extending over the body. The bridge facilitates pressing or clamping the plate in enhanced heat-transferring relation to a substrate heatsink without application of any pressure on the body or other deleterious effects to the body.

Abstract: Disclosed is a method for fabricating semiconductor devices and apparatus that can be used in the practice thereof. A plurality of sets of lead wires is mounted on a reusable primary lead frame. While the lead frame, and thus the lead wires are supported, a pellet is attached to one wire of each of the sets and appropriate flying leads are bonded in place. The sets of lead wires are then transferred to a reusable segmented lead frame, that includes a plurality of elements which are resiliently mounted with respect to each other. Each element supports one set of lead wires. A plurality of cup-shaped mold cavities defined by the mold are filled with a curable fluid encapsulant. The mold is adapted to cooperate with the segmented lead frame as hereinafter set forth. The ends of the lead wires supporting the pellets are immersed in the encapsulant.

Abstract: Disclosed is a semiconductor device and a method for the manufacture thereof. A semiconductor wafer with three stacked regions is provided. An inner region exhibits one conductivity type and the two outer regions exhibit the opposite conductivity type. Isolation regions of the opposite conductivity type are formed by the temperature gradient zone melting process to separate the wafer into a plurality of device regions. Peripheral grooves are cut in one major surface in each device region. The grooves extend into the interior region thus electrically isolating the portion of the major surface within the grooves from the other major surface. The grooves are filled with a passivation material.

Abstract: Disclosed is a photomask and a method for the manufacture thereof. A metal stencil is disposed on a glass substrate such that only preselected areas of the glass which are to be made opaque are exposed. A grit-etch step follows in which depressions are formed in the glass substrate in the preselected areas. Fusible masking material is sprayed in the depressions through the metal stencil. The masking material is preferably in particulate form in a volatile carrier liquid. The carrier liquid is preferably first driven off and, then, the combination is exposed to a relatively high temperature that fuses the masking material to the substrate.

Abstract: Disclosed is a method of manufacturing semiconductor devices by thermomigrating impurities through an oxide layer.

Abstract: Disclosed is a thyristor and a method for the manufacture thereof. An auxiliary dopant, such as gold, is diffused into the cathode emitter region and the area immediately therearound. The auxiliary dopant is selected from among those known to stimulate charge carrier recombination. Consequently charge carrier recombination in the vicinity of the cathode emitter is enhanced and rapid turnoff of the device is promoted. Both SCR and triac embodiments are disclosed.

Abstract: Disclosed is a semiconductor device and a method for the manufacture thereof. A semiconductor wafer with three stacked regions is provided. An inner region exhibits one conductivity type and the two outer regions exhibit the opposite conductivity type. Isolation regions of the opposite conductivity type are formed by the temperature gradient zone melting process to separate the wafer into a plurality of device regions. Peripheral grooves are cut in one major surface in each device region. The grooves extend into the interior region thus electrically isolating the portion of the major surface within the grooves from the other major surface. The grooves are filled with a passivation material.

Abstract: Disclosed is a rectifier pellet and a method for the fabrication thereof. A layer of oxide is grown on a semiconductor wafer that has been diffused to form a plurality of rectifier pellets, and openings are etched in the oxide at locations corresponding to each pellet. Gold is diffused through the openings into a preselected distribution to reduce turnoff time. Grooves are etched to facilitate glass passivation and division of the wafer into pellets.

Abstract: Disclosed is a photomask and a method for the manufacture thereof. A metal stencil is disposed on a glass substrate such that only preselected areas of the glass which are to be made opaque are exposed. A grit-etch step follows in which depressions are formed in the glass substrate in the preselected areas. Fusible masking material is sprayed in the depressions through the metal stencil. The masking material is preferably in particulate form in a volatile carrier liquid. The carrier liquid is preferably first driven off and, then, the combination is exposed to a relatively high temperature that fuses the masking material to the substrate.