LPT(II)-CSTBT™(III) for High Voltage application with ultra robust turn-off capability utilizing novel edge termination design

Abstract

In this paper, the phenomena of current crowding and impact ionization in edge termination of High-Voltage (HV) LPT(II)-CSTBT™(III) is investigated. It is discovered for the first time that these two phenomena act as separated heat sources and induce one local hot spot which causes the thermal destruction in the edge termination during large current and high voltage turn-off switching. A novel edge termination design called “Partial P Collector” is proposed and evaluated. The novel design reduces current crowding and relaxes electric field in the edge termination. Simulated and measured results show that the failure mode of the novel design is determined by current filament phenomenon inside active cell region. It concludes that HV LPT(II)-CSTBT™(III) utilizing Partial P Collector edge termination design has ultra robust turn-off capability without deteriorating other electrical performances.