Improving the reverse blocking capability of carrier stored trench-gate bipolar transistor

Recently, a new IGBT structure, carrier stored trench gate bipolar transistor (CSTBT) was introduced. This structure, modified from the Trench IGBT, preserves the good characteristics of trench IGBT, and also improves the trade off characteristic between the on-state voltage drop and switching loss. However, its reverse blocking voltage is only around 10 V. The low reverse blocking capability of the CSTBT could limit its application in power electronic circuits. To increase the reverse blocking voltage, a p-layer is added in between the P/sup +/-N/sup +/ junction. Simulation shows that the additional p-layer has no effect to the forward characteristic and the turn-on speed of the IGBT, except to increase the reverse blocking voltage to above 80 V.