3.3 kV Multi-Channel AlGaN/GaN Schottky Barrier Diodes with P-GaN Termination

Abstract

This work demonstrates five-channel AlGaN/ GaN Schottky barrier diodes (SBDs) fabricated on a 4-inch wafer with a sheet resistance of 115 Ω/sq. A novel edge termination based on regrown p-GaN is proposed to manage the electric field crowding in the Schottky contact region. A new self-aligned Ohmic process is developed to form sidewall contact to all five channels in a single lithography step. The fabricated lateral SBDs with a breakdown voltage (BV) of 1.65, 2.55, and 3.35 kV show a Baliga's figure of merit of 3.1, 3.5, and 3.6 GW/cm2, respectively, which are the highest among all the similarly-rated power SBDs to date. Based on experimental results, the practical limits of multi-channel AlGaN/GaN lateral devices were found to reach the theoretical vertical GaN limit at a BV over ±2 kV. This suggests the great promise of multi-channel AlGaN/GaN lateral devices for medium- and high-voltage power applications.