Evaluation by Simulation of Quasi-vertical GaN Schottky Barrier Diode With Trench Floating Metal Rings

This paper proposes the trench floating metal ring (TR-FMR) as a novel terminal structure to improve the breakdown voltage (BV) of quasi-vertical GaN Schottky barrier diode (SBD). TR-FMR can disperse the electric field in both horizontal and vertical directions and introduces a new electric field peak into the GaN drift layer, which can make full use of drift layer to withstand voltage. The simulation results show that, compared with PL-FMR, the breakdown of TRFMR SBDs with one metal ring is increased by 180 V, twice than conventional SBD. The depletion region widths at horizontal and vertical directions are larger than PL-FMR, achieving a more uniform electric field distribution. Moreover, the BV can increase with the number of rings increasing, reaching 670 V for three rings. The TR-FMR terminal structure shows great promise for quasi-vertical GaN SBD.