Limitation of switching-self-clamping-mode “SSCM” in high voltage IGBTs

Abstract

In this paper, the self-clamping mechanism and the current filament behavior are investigated during the Switching-Self-Clamping-Mode “SSCM” of high voltage FS-IGBTs. By means of theoretical analysis and numerical device simulation, it is found that the current filament during the self-clamping tends to be stationary, which makes the safe operating area (SOA) of device limited by the local over-current instead of the over-voltage. And for the IGBT with the higher current gain αpnp, the self-clamping is caused by the remaining plasma that cannot be removed.