Abstract: A FET includes a substrate, a buffer layer disposed on the substrate, a channel layer disposed over the buffer layer and a barrier layer disposed over the channel layer. Source, gate and drain electrodes are located over the barrier layer and extend in a longitudinal direction thereon. A portion of the channel and barrier layers define a mesa extending in the longitudinal direction and the source and drain electrodes extend beyond an edge of the mesa. The gate electrodes extend along an edge sidewall of the mesa. A conductive source interconnect is disposed over the buffer layer and have a first end electrically connected to the source electrode. A first dielectric layer is disposed over the buffer layer and over the source interconnect. A gate via is formed in the first dielectric layer. A conductive gate node extends along the buffer layer and electrically connects the portion of the gate electrode extending along the sidewall of the mesa.

Abstract: A circuit includes input drain, source and gate nodes. The circuit also includes a group III nitride enhancement-mode HFET having a source, drain and gate and a voltage shifter having a first terminal connected to the gate of the enhancement mode HFET at a common junction. The circuit also includes a load resistive element connected to the common junction. The drain of the enhancement-mode HFET serves as the input drain node, the source of the enhancement-mode HFET serves as the input source node and a second terminal of the voltage shifter serves as the input gate node.

Abstract: A Schottky contact is disposed atop a surface of a semiconductor. A first Schottky contact metal layer is disposed atop a first portion of the semiconductor surface. A second Schottky contact metal is disposed atop a second portion of the surface layer and adjoins the first Schottky contact metal layer. The first Schottky contact metal layer has a lower work function than the second Schottky contact metal layer.

Abstract: A circuit includes an input drain, source and gate nodes. The circuit also includes a group III nitride depletion mode FET having a source, drain and gate, wherein the gate of the depletion mode FET is coupled to a potential that maintains the depletion mode FET in its on-state. In addition, the circuit further includes an enhancement mode FET having a source, drain and gate. The source of the depletion mode FET is serially coupled to the drain of the enhancement mode FET. The drain of the depletion mode FET serves as the input drain node, the source of the enhancement mode FET serves as the input source node and the gate of the enhancement mode FET serves as the input gate node.

Abstract: A gallium nitride based semiconductor Schottky diode fabricated from a n+ doped GaN layer having a thickness between one and six microns disposed on a sapphire substrate; an n? doped GaN layer having a thickness greater than one micron disposed on said n+ GaN layer patterned into a plurality of elongated fingers and a metal layer disposed on the n? doped GaN layer and forming a Schottky junction therewith. The layer thicknesses and the length and width of the elongated fingers are optimized to achieve a device with breakdown voltage of greater than 500 volts, current capacity in excess of one ampere, and a forward voltage of less than three volts.

Abstract: A repeatable and uniform low doped layer is formed using modulation doping by forming alternating sub-layers of doped and undoped nitride semiconductor material atop another layer. A Schottky diode is formed of such a low doped nitride semiconductor layer disposed atop a much more highly doped nitride semiconductor layer. The resulting device has both a low on-resistance when the device is forward biased and a high breakdown voltage when the device is reverse biased.

Abstract: A guard ring is formed in a semiconductor region that is part of a Schottky junction or Schottky diode. The guard ring is formed by ion implantation into the semiconductor contact layer without completely annealing the semiconductor contact layer to form a high resistance region. The guard ring may be located at the edge of the layer or, alternatively, at a distance away from the edge of the layer. A Schottky metal contact is formed atop the layer, and the edges of the Schottky contact are disposed atop the guard ring.

Abstract: A Schottky contact is disposed atop a surface of a semiconductor. A first Schottky contact metal layer is disposed atop a first portion of the semiconductor surface. A second Schottky contact metal is disposed atop a second portion of the surface layer and adjoins the first Schottky contact metal layer. The first Schottky contact metal layer has a lower work function than the second Schottky contact metal layer.

Abstract: A converter is provided having an AC input and a DC output. The converter includes a rectifier that receives the AC input and that provides a rectifier output, a series connected current to magnetic field energy storage device and current interrupter connected across the rectifier output and a series connected gallium nitride diode and output charge storage device connected between a midpoint of the series connected magnetic field energy storage device and current interrupter and a terminal of the rectifier output and wherein the converter is characterized in not needing a transient voltage suppression circuit.

Abstract: A lateral conduction Schottky diode includes multiple mesa regions upon which Schottky contacts are formed and which are at least separated by ohmic contacts to reduce the current path length and reduce current crowding in the Schottky contact, thereby reducing the forward resistance of a device. The multiple mesas may be isolated from one another and have sizes and shapes optimized for reducing the forward resistance. Alternatively, some of the mesas may be finger-shaped and intersect with a central mesa or a bridge mesa, and some or all of the ohmic contacts are interdigitated with the finger-shaped mesas. The dimensions of the finger-shaped mesas and the perimeter of the intersecting structure may be optimized to reduce the forward resistance. The Schottky diodes may be mounted to a submount in a flip chip arrangement that further reduces the forward voltage as well as improves power dissertation and reduces heat generation.