5kV/3.78mΩ⋅cm² Low Forward Voltage Vertical β-Ga₂O₃ Schottky Rectifier With Field Plate Assisted Deep Mesa Termination

This work demonstrates vertical -Ga2O3 Schottky Barrier Diodes (SBDs) with a field plate assisted deep mesa termination. The 9~ m deep mesa is etched using a self-aligned technique to mitigate electric field crowding at the anode edge. Additionally, a dielectric combination of 100nm Al2O3 and 4. 8~ m SiO2 is deposited to fill the trench, enabling the utilization of a field plate to further reduce the electric field at the anode edge. TCAD simulations demonstrate a substantial reduction in the electric field at the anode edge. Owing to the effective termination, the fabricated SBD shows a high breakdown voltage of 2. 5kV, which is 2. 3 times larger than the unterminated SBDs. The specific on resistance is 3. 78m cm2. Consequently, a high Power Figure of Merit (PFOM) of 1. 65GW/cm2 is hence achieved, which is among the highest in multi-kilovolts Ga2O3 SBDs. Moreover, a remarkably low forward voltage of 1. 45V at 100A/cm2 is also achieved, which is among the lowest in multi-kilovolts Ga2O3 SBDs. The results demonstrate the promising potential of Ga2O3 SBDs for multi-kilovolts applications.