Simulation Study of Trench IGBT with Diode-Clamped P-Well for High dI/dt and dV/dt Controllability

In this paper, a novel trench insulated gate bipolar transistor (TIGBT) with diode-clamped P-well is proposed and investigated by simulation. Compared with the conventional TIGBT with floating P-well, the P-well of the proposed TIGBT is connected with the cathode through two series-connected diodes. In the on-state, for the proposed TIGBT, as the anode voltage is not enough to turn on the two diodes, the holes will be accumulated at the cathode side to enhance the electron injection. In the turn-on process, the P-well potential (V-A) is clamped at a low value by the diodes, decreasing the Miller capacitance and the reverse gate charging current from the P-well region to the gate. Therefore, the gate resistance has better controllability on vertical bar dV(CE)/dt vertical bar and dI(C)(E)/dt due to a lower displacement current (I-G_(dis)) for the proposed TIGBT. Besides, the turn-off energy loss (E-off) is reduced owing to the extra hole path formed by the P-well region. TCAD simulation indicates that, compared with the conventional TIGBT, the Miller capacitance is reduced by 56%. The vertical bar dV(CE)/dt vertical bar and dI(C)(E)/dt of the proposed TIGBT are reduced by 22.1% and 77.6%, respectively. Moreover, the E-off of the proposed one is also reduced by 57.2%.