Separated reverse-conducting insulated-gate bipolar transistor with snapback-free characteristics

A novel reverse-conducting insulated-gate bipolar transistor (RC-IGBT) featuring separated free-wheeling diode (FWD) is proposed. The snapbacks of conventional RC-IGBT are analysed; the electrical characteristics for the proposed RC-IGBT with four kinds of anti-paralleled FWDs are discussed. The results show that the new structure achieves snapback-free characteristics. Moreover, the figures of merit I (FOM I) between V_F and E_off in the forward operation case and FOM II between V_R and Q_rr in the reverse operation case are superior to conventional RC-IGBT. Especially for the integrated merged P-i-N/Schottky (MPS, FWD-A), FOM I can be enhanced by 10%, and FOM II can be enhanced by 50%. In addition, the technological ease of fabrication is another attraction of the proposed device.