5000V Power MOSFET

High voltage solid state switching devices with extremely fast turn-on are needed in applications such as radar and laser modulators. Power MOSFETs match the need for applications with voltages below 1000 volts, but are not presently available with higher voltage ratings. It is proposed to develop a power MOSFET with a voltage rating of 5000 volts. Increasing the blocking voltage unavoidably results in increased on-state resistance per area, so more silicon area will be required to maintain a reasonable (10 ) on-state resistance. Increasing the silicon area results in turn in increased capacitance, which slows turn-on. To maintain fast turn-on, it is proposed to incorporate structural changes to the gate region which have been demonstrated to speed turn-on by reducing the capacitance and series resistance of the gate circuit. Most of the proposed changes are already used in the most recent generation of integrated circuits, but have not yet been adapted by power MOSFET suppliers. The design of the proposed devices will be verified using industry proven process and device simulation programs SUPREM and PISCES, which were developed at Stanford Unversity with support from the US Army.