2.41 kV Vertical P-Nio/n-Ga 2 O 3 Heterojunction Diodes With a Record Baliga's Figure-of-Merit of 5.18 GW/cm 2

In this letter, high-performance p-NiO/β-Ga2O3heterojunction diodes (HJDs) with composite terminal structures, a p-NiO junction termination extension (JTE), and a small-angle beveled field plate (BFP) are demonstrated. By implementing a p-NiO JTE structure, the optimal breakdown voltage (Vbr) ofβ-Ga2O3HJD increases from 955 to 1945 V, and the integration of the small-angle BFP further boosts the breakdown voltage up to 2410 V. An 80-nm thin p-NiO layer is adopted in the heterojunction to reduce the specificon-resistance (Ron,sp), while the composite terminal structures have little effect onRon,sp, due to the super-large lateral spread resistance. Theβ-Ga2O3HJD with composite terminal structures achieves a lowRon,spof 1.12 mΩ·cm2, yielding the highest direct-current Baliga's figure-of-merit (FOM =Vbr2/Ron,sp) among all reported β-Ga2O3diodes with a value of 5.18 GW/cm2,which is about 15% of the theoretical value. These results suggest that the electrical field engineering with a composite terminal structure is a viable and effective technological strategy to enable the realization ofβ-Ga2O3bipolar power rectifiers.