Current filament behavior in IGBTs of different voltage classes investigated by measurements and simulations

New results of 1.7 kV and 6.5 kV single chip IGBTs under repetitive SC events are presented and compared with the results of 1.2 kV IGBTs. An observed current filament pattern as well as the filament lateral distance in 1.7 kV IGBTs are compared with the results of 1.2 kV IGBTs. Device simulation was performed by designing 2D as well as 3D IGBT structures to explain the trend of the filament lateral distance as a function of different voltage class. The current filament pattern produced with the help of 3D simulation was compared with the observed current filaments from experimental results. Possible reasons for the mismatch between measurement and 3D-simulation results are discussed.