2.3 kV low leakage vertical (001) β-Ga2O3 diodes enabled by a synergistic guard ring and beveled field plate

This study presents a vertical (001) β-Ga2O3 Schottky barrier diode (SBD) incorporating a composite edge termination structure, which combines a nitrogen-implanted guard ring (GR) with a small-angle beveled field plate (BFP). Leveraging technology computer-aided design simulations grounded in semiconductor physics, we developed and optimized the device's geometric structure. Integration of GR with BFPs enables suppression of the anode-edge electric-field peak without degrading the favorable forward conduction characteristics. Thanks to this optimized termination design, the fabricated diode achieves a breakdown voltage (Vbr) of 2.3 kV—6.5 times higher than that of nonterminated devices—along with a specific on-resistance (Ron,sp) of 3.19 mΩ cm2. These properties yield a high Baliga's figure of merit of 1.71 GW/cm2. Furthermore, at a reverse bias of −1500 V, the device demonstrates a low leakage current density of less than 1 μA/cm2. This work presents a feasible approach to improve the performance of β-Ga2O3 SBDs, paving the way for their adoption in power electronics.