文摘
The voltage clamping mode appears in the inductive turn-off waveforms of a CSTBT under rated operating conditions. An abnormal gate voltage bump is also observed, which is known as a precursor of instable dynamic avalanche. The comparison between the inductive turn-off characteristics of the CSTBT and another FS-IGBT imply that the CS layer is the root cause of the CSTBT’s abnormal dynamic avalanche characteristics. The CS layer's impact on the dynamic avalanche is clarifed, which reveal the CSTBT’s dynamic avalanche mechanism. The negative gate capacitance effect is also investigated to clarify the mechanism of the gate voltage bump. The mixed-mode numerical simulation is utilized to reproduce the CSTBT’s dynamic avalanche behavior. The simulation results validate the proposed dynamic avalanche mechanisms.