Analytical Design and Modelling of GaN Vertical Trench Junction Barrier Schottky Diodes

We report GaN vertical trench junction barrier Schottky (TJBS) diodes and systematically investigate the impacts of the key design parameters on the reverse and forward characteristics of GaN-based TJBS diodes by numerical simulation. Compared with conventional planar junction barrier Schottky (PJBS) diodes, the TJBS structure can suppress the electric field at the Schottky interface more effectively by taking advantage of the electric field shielding effect. We found that the electric field profile can be influenced by the doping concentration, thickness and spacing of p-GaN, as well as the depth and angle of the trench sidewalls. Furthermore, the effect of the cross-sectional profile on the forward characteristics of the TJBS diodes are investigated and the analytical model of the forward conduction is also developed. The results can pave the way towards a high-power, high-voltage, and low-loss GaN vertical Schottky barrier diodes for high-efficiency power system applications.