Fabrication and characterization of optical float-zone (100) β-Ga2O3 Schottky diodes

We conducted a rapid fabrication of Ga2O3 vertical Schottky barrier diodes using Ti/Au for ohmic contacts and Ni/Au for Schottky contacts on a (100) Sn-doped β-Ga2O3 grown by the optical float-zone method and analyzed the device characteristics and performance. Approximately 190 diodes were fabricated with varying contact sizes—50 and 100 μm—and different contact shapes, including circular, square, and squircle configurations. Of these, eighteen devices were tested for their current–voltage and capacitance–voltage characteristics. The best-performing device achieved a breakdown voltage of 52 V. Our studies show that, in addition to the intrinsic defects within the material, electric field-induced defects may also contribute to the increased leakage current, catastrophic damage, and surface cracks mainly along the [010] and also on [001] directions beneath the Schottky contacts, as confirmed by scanning electron microscopy. Optimizing the device design and fabrication process, lowering doping concentrations, and reducing intrinsic defects in the drift layers could significantly enhance the performance and reliability of Ga2O3-based Schottky diodes for next-generation power electronics components.