Low Turn-on and Surge-Robust β-Ga2O3 Heterojunction Barrier Schottky Diodes Enabled by Conductivity Modulation

We report β-Ga2O3 heterojunction barrier Schottky (HJBS) diodes featuring a low turn-on voltage (Von) and high surge robustness. A p-type NiO overlayer, fully covering the tungsten-based Schottky contacts, enables efficient minority carrier injection, thereby lowing Von and enhancing surge performance. Fabricated small-area diodes (0.15 × 0.12 mm2) exhibit a breakdown voltage (BV) of 1.4 kV and a Von of 0.51 V. Packaged large-area devices (3 × 3 mm2) deliver 6 A at a 2 V forward bias and sustain surge currents up to 50 A, attributed to conductivity modulation by the p-NiO overlayer. TCAD simulations confirm that the proposed HJBS structure significantly reduces peak lattice temperatures compared to conventional designs. These results demonstrate the strong potential of β-Ga2O3 HJBS diodes for high-efficiency, low-loss power switching applications with enhanced transient tolerance.