Simulation and Characterization Studies of GaN-Based Quasi-Vertical MIS SBD

In order to improve the performance of GaN-based quasi-vertical MIS SBD, this paper proposes and designs a new MIS SBD with MIS (metal-insulation-semiconductor) terminal structure, and optimizes its structural parameters via simulation. The characteristic simulation result shows that the on-resistance of conventional quasi-vertical SBD and new quasi-vertical MIS SBD are 0.565mΩ•cm2 and 0.556mΩ•cm2 respectively. And the breakdown voltage is increased from 632V to 1056V. After optimization, including the length and thickness of the insulation dielectric layer and the thickness of N-GaN layer, the on-resistance of quasi-vertical MIS SBD increases slightly to 0.648mΩ•cm2, but the breakdown voltage reaches 1624V. Besides, the new structure can effectively alleviate the current crowding phenomenon, alleviate the peak electric field at the edge of the anode in reverse bias, and make the electric field distribution in the device more uniform.