CSTBT™ technology for high voltage applications with high dynamic robustness and low overall loss

This paper discusses the edge termination design of high-voltage insulated gate bipolar transistors with large current turn-off switching operation. We discovered that the phenomena of current crowding and impact ionization act as separated heat sources and induce one local hot spot that causes thermal destruction in the edge termination during the turn-off switching period. Optimizing the backside hole injection efficiency and relaxing the electric field of the surface pn junction edge at the edge termination region prevent the above problems. These concepts benefit the dynamic ruggedness under hard-switching conditions. This paper presents our novel edge termination design that achieves robust turn-off capability without deteriorating other performances of the device.