Evaluation on the electro-thermal instability process of thermal runaway under high temperature based on TCAD

Thermal runaway is one of the major failure modes for IGBTs. In the present work, the thermal runaway is theoretically analyzed and quantitatively characterized based on TCAD models. Firstly, the mechanism of thermal runaway under HTB (High Temperature Blocking) condition and short-circuit condition was analyzed in theoretical. Next, a TCAD model was proposed and improved to realize the equivalence of thermal network parameters. Subsequently, the thermal runaway under HTB and short-circuit condition was investigated by the TCAD model respectively. The experimental results further validate the results of simulations. The paper reveals the failure mechanism and of thermal runaway under HTB and short-circuit condition and gives the failure boundary of thermal runaway. It may also provide a feasible solution for evaluating the SOA, which is essential for the application of IGBT under extreme working conditions.