Improvement of breakdown voltage of GaN-on-GaN p-n Junction Diodes with Shallow Bevel Termination for High Power Applications

摘要

One of the major factors limiting the performance of vertical GaN devices, is the electric field crowding at a device edge , Very recently, Maeda et al. showed that this problem can be effectively eliminated in beveled- mesa structures by introducing n and p-layers with comparable doping concentrations , In this work, we propose another approach for reducing electric field crowding in the bevel mesa structures. We show, using two- dimensional TCAD simulations that due to implementation of P -type regions into the bevel mesa structures (see Fig. 1, P_2 areas) it is possible to obtain the uniform avalanche effect and thus significant enhancement of the breakdown voltage (BV).