NiO/β-Ga2O3 heterojunction diodes with ultra-low leakage current below 10−10 A and high thermostability

The 10 nm p-NiO thin film is prepared by thermal oxidation of Ni on β -Ga 2 O 3 to form NiO/ β -Ga 2 O 3 p–n heterojunction diodes (HJDs). The NiO/ β -Ga 2 O 3 HJDs exhibit excellent electrostatic properties, with a high breakdown voltage of 465 V, a specific on-resistance ( R on,sp ) of 3.39 mΩ⋅cm 2 , and a turn-on voltage ( V on ) of 1.85 V, yielding a static Baliga's figure of merit (FOM) of 256 MW/cm 2 . Also, the HJDs have a low turn-on voltage, which reduces conduction loss dramatically, and a rectification ratio of up to 10 8 . Meanwhile, the HJDs' reverse leakage current is essentially unaffected at temperatures below 170 °C, and their leakage level may be controlled below 10 −10 A. This indicates that p-NiO/ β -Ga 2 O 3 HJDs with good thermal stability and high-temperature operating ability can be a good option for high-performance β -Ga 2 O 3 power devices.