A simulation study of field plate termination in Ga₂O₃ Schottky barrier diodes

In this work, the field plate termination is studied for Ga₂O₃ Schottky barrier diodes (SBDs) by simulation. The influence of field plate overlap, dielectric material and thickness on the termination electric field distribution are demonstrated. It is found that the optimal thickness increases with reverse bias increasing for all the three dielectrics of SiO₂, Al₂O₃, and HfO₂. As the thickness increases, the maximum electric field intensity decreases in SiO₂ and Al₂O₃, but increases in HfO₂. Furthermore, it is found that SiO₂ and HfO₂ are suitable for the 600 V rate Ga₂O₃ SBD, and Al₂O₃ is suitable for both 600 V and 1200 V rate Ga₂O₃ SBD. In addition, the comparison of Ga₂O₃ SBDs between the SiC and GaN counterpart reveals that for Ga₂O₃, the breakdown voltage bottleneck is the dielectric. While, for SiC and GaN, the bottleneck is mainly the semiconductor itself.