3.0 kV β-Ga₂O₃-Based Vertical p-n Heterojunction Diodes With Helium- Implanted Edge Termination

We demonstrated the vertical NiO/β-Ga2O3 p-n heterojunction diodes (HJDs) with a high breakdown voltage (VBR) of 3000 V and a low ON-resistance (Ron,sp) of 3.12 mΩ cm2, resulting in a Baliga's figure of merit (FOM) of 2.88 GW/cm2. Specifically, an efficient and low-damage edge termination (ET) formed by the implantation of lightweight Helium atoms was introduced to inhibit the high electric field at the p-n junction of HJDs, thereby increasing VBR of devices from 1330 to 3000 V. The reverse leakage mechanisms were fit and analyzed, revealing distinct breakdown mechanisms in He-implanted devices. The simulation results confirmed the peak electric field at the p-n junction of devices can be effectively suppressed by He-implanted ET. Meanwhile, a narrow change of devices' Ron,sp occurred after He implantation and the low-Ron,sp forward conduction of devices was confirmed by efficient charge transfer of heterojunction with density functional theory (DFT) calculation. This work may provide a new insight into the design and fabrication of high-power, lowloss β-Ga2O3 bipolar power devices.