Simulation Study of 4H-SiC Low Turn-Off Loss and Snapback-Free Reverse-Conducting Gate Turn-Off Thyristor with N-Float Structure

In this study, a novel integrated 4H-SiC reverse-conducting gate turn-off thyristor (GTO) featuring an N-type floating (NF) structure is proposed. The proposed NF-structured 4H-SiC GTO outperforms conventional reverse-conducting GTOs in forward conduction, effectively eliminating the snapback phenomenon. This is achieved by increasing lateral resistance above the P-injector and modifying the electron current path during early turn-on. NF structures with a doping concentration of 2 x 1014 cm-3 and thicknesses exceeding 4 mu m have been indicated to successfully eliminate the snapback phenomenon. Moreover, the anode-shorted structure enhances the GTO's breakdown voltage and concurrently reduces turn-off losses by 85% at low current densities.