Recessed-anode AlGaN/GaN diode with a high Baliga's FOM by combining a p-GaN cap layer and an anode-connected p-GaN buried layer

Abstract

In this article, a recessed-anode AlGaN/GaN Schottky barrier diode with a p-GaN cap layer and an anode-connected p-GaN buried layer was proposed and optimized by Silvaco TCAD. The impact of different structural parameters on the trade-off between breakdown voltage and differential specific on-resistance were systematically investigated. Compared with the conventional recessed-anode SBD, the introduction of a p-GaN buried layer with an optimum distance from 2DEG channel can improve the breakdown voltage mildly, reduce the on-resistance and increase the surge current capability obviously at relatively high forward bias. Besides, a p-GaN cap layers slightly decreases the current density but demonstrates an obvious improvement in the breakdown voltage. Therefore, a combining of the p-GaN buried layer and the p-GaN cap layer is promising to achieve the better trade-off between on-resistance and breakdown voltage, resulting in a higher Baliga's FOM.