2.83-kV double-layered NiO/-Ga₂O₃ vertical p-n heterojunction diode with a power figure-of-merit of 5.98 GW/cm²

This work demonstrates high-performance NiO/& beta;-Ga2O3 vertical heterojunction diodes (HJDs) with double-layer junction termination extension (DL-JTE) consisting of two p-typed NiO layers with varied lengths. The bottom 60-nm p-NiO layer fully covers the & beta;-Ga2O3 wafer, while the geometry of the upper 60-nm p-NiO layer is 10 & mu;m larger than the square anode electrode. Compared with a single-layer JTE, the electric field concentration is inhibited by double-layer JTE structure effectively, resulting in the breakdown voltage being improved from 2020 to 2830 V. Moreover, double p-typed NiO layers allow more holes into the Ga2O3 drift layer to reduce drift resistance. The specific on-resistance is reduced from 1.93 to 1.34 m & omega;& BULL;cm(2). The device with DL-JTE shows a power figure-of-merit (PFOM) of 5.98 GW/cm(2), which is 2.8 times larger than that of the conventional single-layer JTE structure. These results indicate that the double-layer JTE structure provides a viable way of fabricating high-performance Ga2O3 HJDs.