Investigation of TCAD Calibration for Saturation and Tail Current of 6.5kV IGBTs

In this work we focus on two calibration methods to clarify a key point of TCAD calibration for turn-off waveforms and IV characteristics including the saturation currents of IGBTs at the same time. Simulated results with the method based on adjustments of the surface N+ and P+ depth ratio reproduce measured results of all calibration targets reasonably in terms of time and accuracy. On the other hand, simulated results by mainly calibrating parameters of the velocity saturation model for saturation currents hardly reproduce all calibration targets simultaneously. We explain the reason using the roughly approximated criteria of the dynamic punch-through oscillation and dynamic avalanche. We also analyze the temperature dependence of the tail current briefly which is one of the important design items of IGBTs.