The Investigation of β-Ga₂O₃ Schottky Diode with Floating Field Ring Termination and the Interface States

In this paper, we fabricated the vertical β-Ga₂O₃ Schottky barrier diodes with floating metal ring (FMR) edge termination structure. As the distance between the major Schottky junction and the FMR increasing, the breakdown voltage increases to 143, 161, 188 and 172 V, respectively, about 20.17%, 35.29%, 57.98% and 44.54% improvement in comparison with that without FMR. Under constant current stress, the variation of applied voltage indicates that the barrier height increases by the electron capture at the interface states while the barrier height decreases by the electron release. Furthermore, based on the excellent fitting of G_p/ω measurement data, the extracted trap levels are within the range of 0.87–0.90 eV below the conduction band edge and the corresponding trap density increases from 1.24 × 10¹² cm⁻² · eV⁻¹ to 1.71 × 10¹³ cm⁻² · eV⁻¹, which is in good agreement with previously reported theoretical and experimental results.