Breakdown up to 12 Kv in NiO/β-Ga₂O₃ Vertical Heterojunction Rectifiers

Vertical heterojunction NiO/β n-Ga 2 O/n + Ga 2 O 3 rectifiers fabricated on 15 µm thick drift layers with carrier concentration 8.8 x10 15 cm -3 and employing simple dual-layer PECVD SiNx/SiO 2 edge termination demonstrate breakdown voltages (V B ) up to 12 kV, on-voltage (V ON ) of ~2.2V and on-state resistance R ON of 11.1-12 mΩ.cm 2 . The breakdown field is ~8 MV. cm -1 , close to the commonly accepted theoretical value. The associated power figure-of-merit, V B 2 /R ON is 13 GW·cm -2 . By sharp contrast, Schottky rectifiers concurrently fabricated on the same drift layers had maximum V B of 2.9 kV, but lower V ON of 0.71-0.75 V. Transmission electron microscopy showed an absence of lattice damage between the PECVD and sputtered films within the device and the underlying epitaxial Ga 2 O 3 . The key advances are thicker, lower doped drift layers and optimization of edge termination design and deposition processes. Figure 1