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.