Electric field reconfiguration in W/ β -Ga2O3 Schottky barrier diodes under negative bias stress

In this work, the characteristics of W/Ga2O3 Schottky barrier diodes with Al2O3 passivation under negative bias stress (NBS) are investigated. Interestingly, the NBS treatment yields a significant 91% reduction in reverse leakage current (Ileakage) and a 29.7% enhancement in breakdown voltage (Vbreakdown), with negligible impact on forward I–V characteristics. The observed behavior is attributed to electron trapping near the anode edge, with an activation energy of 0.44–0.49 eV and approximately 0.75 eV. Technical computer-aided design simulations validate that the trapped negative charges function as a virtual field plate, which redistributes the electric field and mitigates the field peak at the anode edge. Our findings highlight a reversible field-modulation mechanism via interface charge engineering, offering insights into the reliability and performance optimization of Ga2O3-based power electronics.