Selective High-Resistance Zones Formed by Oxygen Annealing for β-Ga₂O₃ Schottky Diode Applications

Selective area doping technique is essential for diversifying semiconductor device structures. In this letter, selective high-resistance zones on β-Ga₂O₃ wafers were successfully achieved by a high-temperature oxygen annealing process. Polysilicon, which proved to have an ideal blocking capability against oxygen annealing ambient, was employed as an annealing cap layer to prevent local carrier concentration changes during annealing. Based on this unique process approach, we further demonstrate a high-resistance anode edge termination of Schottky barrier diodes, which can considerably reduce the leakage current and increase the breakdown voltage of the devices. This research broadens the device manufacturing method and promotes the development of Ga₂O₃ devices.