Dependence of field plate parameters on dielectric constant in a 4H-SiC Schottky diode

In this work, we report the dependence of optimum value of field plate parameters, viz., overlap length and dielectric thickness, on dielectric constant of field-plate dielectric in a 1900V, Ni/4H-SiC Schottky diode. Field plate overlap length and dielectric thickness are optimized for different device processing-compatible dielectric materials: SiO₂, Si₃N₄, Al₂O₃ and HfO₂. The results show that the optimum field plate overlap length decreases and dielectric thickness increases in the presence of higher-k field plate dielectrics.