Impacts of the 4H-SiC/SiO2 interface states on the switching operation of power MOSFETs

Impacts of the 4H-SiC/SiO₂ interface states on the switching operation of power MOSFETs are evaluated. The energy distributions of the interface states are characterized using measured C-V curves of the MOS capacitors with the aid of TCAD simulation. The effect of nitrogen incorporation into the SiC/SiO₂ interface via post-oxidation anneal (POA) on reducing the interface states is confirmed by the extracted energy distributions. The effect of POA on turn-on/off energy losses of the switching circuit is quantitatively evaluated using mixed-mode TCAD simulation with the extracted interface state parameters.