2.41 kV Vertical P-Nion-Ga2O3 Heterojunction Diodes With a Record Baligas Figure-of-Merit of 5.18 GWcm2

In this letter, high-performance p-NiO/ss-Ga2O3 heterojunction 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) of ss-Ga2O3 HJD 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 specific ON-resistance (Ron,sp), while the composite terminal structures have little effect on Ron,sp, due to the super-large lateral spread resistance. The ss-Ga2O3 HJD with composite terminal structures achieves a low Ron, sp of 1.12 mO center dot cm2, yielding the highest direct-current Baliga's figure-of-merit (FOM = Vbr2/Ron,sp) among all reported ss-Ga2O3 diodes 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 of ss-Ga2O3 bipolar power rectifiers.

Automated summary

By implementing a composite terminal structure with a p-NiO junction termination extension and a small-angle beveled field plate, high-performance p-NiO/ss-Ga2O3 heterojunction diodes were successfully demonstrated. This structure significantly increases the breakdown voltage of ss-Ga2O3 and achieves low ON-resistance, making it a promising candidate for various applications.