Comprehensive device modeling for AlGaN/GaN based Schottky barrier diodes with beveled p-GaN termination to control electric field

In this article, we have systematically investigated the impact of different structural parameters on the electrical characteristics for AlGaN/GaN based Schottky barrier diodes (SBDs) with beveled p-GaN termination by using TCAD simulation tools. The p-GaN termination can decrease the electric field at the Schottky contact region, thereby suppressing the electrical field magnitude in the Schottky contact region. Then, the breakdown voltage can be enhanced without remarkably sacrificing the forward conduction characteristics. However, in spite of the reduced electric field magnitude in the Schottky contact region, the electric field will possess the peak value at the edge of p-GaN termination. Therefore, the premature breakdown can occur when the electric field therein reaches critical value. Hence, we have comprehensively manipulated the electric field distributions by designing different p-GaN terminations and detailed optimization strategy for the AlGaN/GaN based Schottky barrier diodes has been conducted. Moreover, we find that the strong electric field at the p-GaN termination edge can be reduced by using beveled p-GaN termination, which can extend the electric potential into the bulk GaN region. With the developed defected-related physical models, we also find that the p-GaN termination suppress the capture and release process for the carriers by defects, which improves the dynamic characteristics for the proposed devices.