US Patent 7598567 Power switching semiconductor devices including rectifying junction-shunts

A semiconductor device includes a drift layer having a first conductivity type and a body region adjacent the drift layer. The body region has a second conductivity type opposite the first conductivity type and forms a p-n junction with the drift layer. The device further includes a contactor region in the body region and having the first conductivity type, and a shunt channel region extending through the body region from the contactor region to the drift layer. The shunt channel region has the first conductivity type. The device further includes a first terminal in electrical contact with the body region and the contactor region, and a second terminal in electrical contact with the drift layer. The shunt channel region has a length, thickness and doping concentration selected such that: 1) the shunt channel region is fully depleted when zero voltage is applied across the first and second terminals, 2) the shunt channel becomes conductive at a voltages less than the built-in potential of the drift layer to body region p-n junction, and/or 3) the shunt channel is not conductive for voltages that reverse biase the p-n junction between the drift region and the body region.