Abstract: In planar silicon semiconductor devices of the PN junction type, field plates overlie the silicon dioxide-silicon nitride film on the device surface to inhibit inversion formation of conductive channels on the device surface. The field plates are connected to a more heavily doped zone on one side of a PN junction and extend some distance over the lightly doped zone on the other side of the PN junction.At high reverse biases, the presence of trapping centers produces a charge level at the device surface, resulting in current channeling which produces excessive reverse leakage current. This effect is avoided or reduced by omitting the silicon nitride layer in a portion overlying the more lightly doped zone and spaced away from the PN junction boundary. This omission eliminates a portion of the oxide-nitride interface which appears to be the locus of such trapping centers.

Abstract: A gate-controlled bidirectional switching device has two main terminals on opposite major surfaces of the device. A single gate terminal located adjacent one of the main terminals on one of the major surfaces receives a signal biased with respect to said one terminal to trigger the device into conduction. The device conducts current in either direction through the main terminals, depending on the polarity of an applied bias potential across the main terminals. By controlling the resistivities or the widths of two base regions in the device with respect to each other, a trigger current for switching the device from a nonconductive state to conduct current in the one direction is adjusted with respect to that required to switch the device to conduct current in the other direction.

Abstract: A semiconductor junction-isolated PNPN crosspoint switch array has a plurality of crosspoint switches that are each formed of four regions of alternating conductivity type in a semiconductor substrate. Low enough leakage to allow the crosspoint switch array to be used in large telephone switching systems is achieved by proper selection of the thickness of the semiconductor regions and by appropriate gold doping thereof.

Abstract: A gate-controlled bidirectional switching device has two main terminals on opposite major surfaces of the device. A single gate terminal located adjacent one of the main terminals on one of the major surfaces receives a signal biased with respect to said one terminal to trigger the device into conduction. The device conducts current in either direction through the main terminals, depending on the polarity of an applied bias potential across the main terminals. By controlling the resistivities or the widths of two base regions in the device with respect to each other, a trigger current for switching the device from a nonconductive state to conduct current in the one direction is adjusted with respect to that required to switch the device to conduct current in the other direction.