Novel fast-switching P-poly trench collector reverse conducting IGBT with different N-buffer position

A novel fast-switching P-poly trench collector reverse-conducting insulated gate bipolar transistor (RC-IGBT) with different N-buffer position (DBP) is proposed and investigated. Firstly, the N-buffer on P-poly Trench-Collector (TC) not on P+ and N+ collector will unaffected realize snapback-free with and without interface charge exist in the forward conduction. Secondly, N-buffer on TC can keep the fast extraction channel to the N+ collector open all the time, so that the ultralow turn-off loss (EOFF) can be achieved in IGBT mode, and the reverse recovery charge (Qrr) can be reduced in diode mode. Thirdly, N-buffer on TC makes the electric field distribution more uniform during forward blocking, thus further improving the breakdown voltage (BV). Fourth, N-buffer on TC can also provide more electrons to reduce forward peak recovery voltage (VFRM) during diode forward recovery mode. Compared with PNTC RC-IGBT, the proposed RC-IGBT enjoys lager breakdown voltage, and can reduce VFRM by 83%, Qrr by 27%, and the EOFF by 36%.