Turn-off behaviour of epitaxial planar and trench gate IGBTs and nonepitaxial planar gate IGBT under hard and soft switchings

The results of investigation on turn-off dynamic operations of IGBTs are pr esented in the paper. Three-types of IGBTs which have planar and trench gat e structures by epitaxial wafer and planar gate structure by nonepitaxial w afer are compared under conditions of hard and soft switching commutation t opologies. Collector-emitter voltage and collector current waveforms of eac h IGBT and power losses are analysed under conditions of various parameters through simulation and in experiment. Moreover. carrier behaviour, electri c Field and potential distributions inside the chips are studied by simulat ion technique. It is noted that the trench gate IGBT has an advantage over the other-types for the hard switching application from the point of view o f switching losses, and both the planar and trench gate IGBTs on the basis of an epitaxial wafer are more suitable for soft switching applications bec ause of lower switching and on-state losses.