Design of bevel junction termination extension structure for high-performance vertical GaN Schottky barrier diode

In this work, a vertical GaN Schottky barrier diode with a bevel junction termination extension termination was designed by Silvaco TCAD. The effect of drift layer doping concentration, p-GaN doping concentration and bevel angle are evaluated extensively. With the optimum parameters, the bevel junction termination extension provides conduction path in the forward bias region to reduce the on-resistance and suppresses the electric field crowding in the reverse bias region. Furthermore, the Schottky contact characteristics are not affected in the relatively low bias region. The bevel junction termination extension is promising to achieve low turn-on voltage, low on-resistance and high breakdown voltage. • Bevel junction termination extension termination was designed for vertical GaN SBDs. • The bevel termination suppresses the electric field crowding under reverse bias. • The proposed structure is promising to achieve low turn-on voltage, low on-resistance and high breakdown voltage.