Abstract: An accumulation-mode field effect transistor includes a drift region of a first conductivity type, channel regions of the first conductivity type over and in contact with the drift region, and gate trenches having sidewalls abutting the channel regions. The gate trenches extend into and terminate within the drift region. The transistor further includes a first plurality of silicon regions of a second conductivity type forming P-N junctions with the channel regions along vertical walls of the first plurality of silicon regions. The first plurality of silicon regions extend into the drift region and form P-N junctions with the drift region along bottoms of the first plurality of silicon regions.

Abstract: In one embodiment of the present invention, a trench MOS-gated transistor includes a first region of a first conductivity type forming a pn junction with a well region of a second conductivity type. The well region has a flat bottom portion and a portion extending deeper than the flat bottom portion. A gate trench extends into the well region. Channel regions extend in the well region along outer sidewalls of the gate trench. The gate trench has a first bottom portion which terminates within the first region, and a second bottom portion which terminates within the deeper portion of the well region such that when the transistor is in an on state the deeper portion of the well region prevents a current from flowing through those channel region portions located directly above the deeper portion of the well region.

Abstract: A quick punch-through integrated gate bipolar transistor (IGBT) includes a drift region and a gate. The drift region has a drift region dopant concentration and a drift region thickness. The gate has a gate capacitance. The drift region dopant concentration, drift region thickness and gate capacitance are adjusted dependent at least in part upon the PNP gain of the IGBT to maintain the potential difference between the gate and emitter at a level greater than the IGBT threshold voltage when the collector voltage reaches the bus voltage. This insures that the hole carrier concentration remains approximately equal to or greater than the drift region dopant concentration when the depletion layer punches through to the buffer region during the turn-off delay. Thus, the collector voltage overshoot and the rate of change of voltage and current are controlled, and electromagnetic interference is reduced, during turn off.

Abstract: A semiconductor diode includes a first semiconductor layer including a dopant having a first conductivity type. A second semiconductor layer is adjacent the first semiconductor layer and includes a dopant having the first conductivity type and having a dopant concentration less than a dopant concentration of the first semiconductor layer. Adjacent the second semiconductor layer is a third semiconductor layer including a dopant having the first conductivity type and having a dopant concentration greater than the dopant concentration of the second semiconductor layer. A fourth semiconductor layer is adjacent the third semiconductor layer and includes a dopant of a second conductivity type. Respective contacts are connected to the first and fourth semiconductor layers.

Abstract: A trench MOS-gated device having an upper surface includes a substrate having an upper layer of doped monocrystalline semiconductor material of a first conduction type. A gate trench in the upper layer has sidewalls and a floor lined with a first dielectric material and a centrally disposed core that is formed of a second dielectric material and extends upwardly from the first dielectric material on the trench floor to contact an interlevel dielectric layer overlying the gate trench. The remainder of the trench is substantially filled with a conductive material that encompasses and contacts the core of second dielectric material. A doped well region of a second conduction type overlies a drain zone of the first conduction type in the upper layer, and a heavily doped source region of the first conduction type contiguous to the gate trench and a heavily doped body region of the second conduction type are disposed in the well region at the upper surface.

Abstract: A trench MOS-gated device having an upper surface includes a substrate having an upper layer of doped monocrystalline semiconductor material of a first conduction type. A gate trench in the upper layer has sidewalls and a floor lined with a first dielectric material and a centrally disposed core that is formed of a second dielectric material and extends upwardly from the first dielectric material on the trench floor to contact an interlevel dielectric layer overlying the gate trench. The remainder of the trench is substantially filled with a conductive material that encompasses and contacts the core of second dielectric material. A doped well region of a second conduction type overlies a drain zone of the first conduction type in the upper layer, and a heavily doped source region of the first conduction type contiguous to the gate trench and a heavily doped body region of the second conduction type are disposed in the well region at the upper surface.

Abstract: A quick punch-through integrated gate bipolar transistor (IGBT) includes a drift region and a gate. The drift region has a drift region dopant concentration and a drift region thickness. The gate has a gate capacitance. The drift region dopant concentration, drift region thickness and gate capacitance are adjusted dependent at least in part upon the PNP gain of the IGBT to maintain the potential difference between the gate and emitter at a level greater than the IGBT threshold voltage when the collector voltage reaches the bus voltage. This insures that the hole carrier concentration remains approximately equal to or greater than the drift region dopant concentration when the depletion layer punches through to the buffer region during the turn-off delay. Thus, the collector voltage overshoot and the rate of change of voltage and current are controlled, and electromagnetic interference is reduced, during turn off.

Abstract: A power semiconductor device has an integral source/emitter ballast resistor. The gate has partial gate structures spaced apart from each other. Emitter resistors are provided beneath sidewall spacers on the ends of the gate structures. The emitter resistors have little effect on the threshold voltage under normal operating conditions, but rapidly saturate the device during short circuit conditions. This in turn increases the short circuit withstand capability o the device.

Abstract: A semiconductor switching device includes a plurality of adjacent heterojunction-gate static-induction transistor (SIT) unit cells connected in parallel in a monocrystalline silicon carbide substrate having first and second opposing faces, a relatively highly doped silicon carbide drain region adjacent the first face and a relatively highly doped silicon carbide source region adjacent the second face. A relatively lightly doped drift region is also provided in the substrate and extends between the drain region and source region. A plurality of trenches are also provided in the substrate so that sidewalls of the trenches extend adjacent the drift region. Each trench preferably contains a relatively highly doped second conductivity type nonmonocrystalline silicon gate region comprised of a material selected from the group consisting of polycrystalline silicon or amorphous silicon. These gate regions form P-N heterojunctions with the drift region at the sidewalls and bottoms of the trenches.