Impact of Implanted Edge Termination on Vertical β -Ga₂O₃ Schottky Barrier Diodes Under off-State Stressing

Both dc and OFF-state stress characteristics of vertical beta-gallium oxide $(\beta $ -Ga2O3) Schottky barrier diodes (SBDs) with or without ion-implanted edge termination (ET) were comparatively analyzed in this work. An implanted ET by He and Mg ions can effectively increase breakdown voltage (BV) from 0.5 to 1.0 and 1.5 kV, respectively, by sacrificing minimal forward characteristics. However, SBDs with ion ET exhibited a larger degradation than SBDs without ion ET after OFF-state stressing, especially for Mg ion-implanted ET, which caused more severe lattice damage at the edge of the anode by transmission electron microscopy (TEM) verification. The OFF-state characteristics were investigated by conventional measure/stress/measure (MSM) with reverse stress biases applied from −100 to −1000 V. The ion-implanted ET brings two effects on the device characteristics: 1) the increase of Schottky barrier height ( $\Phi _{B}$ ) in both dc and OFF-state stress characteristics caused by the virtual gate-like effect and leading to an increased ${V}_{ON}$ and 2) the increase of ${R}_{ON,SP}$ in the forward dc characteristics is attributed to the increase of anode resistance and lateral depletion.