Approaching homogeneous switching of MCT devices: experiment and simulation

Problems in scaling the MCT (MOS-controlled thyristor) to higher turn-off currents (I/sub TGM/) still need to be resolved. It is shown experimentally that these performance problems are related to design features occuring at the boundary of the device and at the locations of the MOS turn-on cells. The simulation of complete turn-on-turn-off cycles over a realistic time scale of an improved MCT boundary structure has also been carried out. The results reveal detailed physical insight into the mechanisms involved in the switching of the cell ensemble. It is shown that the device boundary can be improved by layout measures to yield a uniform current distribution throughout the entire turn-off of the MCT device. >