A new lateral AlGaN/GaN Schottky barrier diode combining with floating metal rings and P-guard rings for high breakdown voltage

Abstract

The lateral AlGaN/GaN Schottky barrier diode combining floating metal rings (FMR) and P-guard rings (PGR) structures (PGFMR-SBD) is proposed. The forward and reverse characteristics of the PGFMR-SBD are simulated by Silvaco software. The simulation results show that, the breakdown voltage of the PGFMR-SBD can improve to -685V, compared with the conventional SBD of -250 V. Furthermore, in order to analyze the mechanism of the reverse breakdown voltage improvement, the electric field distribution of the PGFMR-SBD is simulated. The result shows that, due to the introduction of p-GaN, the PN junction formed by the p-GaN layer1expands the depletion region at anode edge more effectively than the Schottky junction. Three new electric field peaks appear at PGFMR, and the electric field distribution becomes more uniform in the PGFMR-SBD. Meanwhile, the PGFMR can begin to withstand voltage at lower reverse voltage. Therefore, the electric field concentration effect at the anode edge is alleviated by PGFMR, thus improving the breakdown voltage.