Demonstration of Record Breakdown up to 13.5 kV in NiO/β-Ga2O3 Vertical Rectifiers

Significant strides in Ga 2 O 3 power rectifiers have occurred since the demonstration of a 1 kV device in 2017 [1] . This progress includes enhanced edge termination methods and NiO as a p-type layer, utilized in heterojunction diodes (HJDs) with superior breakdown voltages compared to conventional Schottky rectifiers [ 2 – 4 ] . Vertical Schottky Barrier Diodes (SBDs) are favored for power switching due to a proportional relationship between the breakdown voltage (V B ) and the drift layer thickness, augmenting power density and blocking voltage while minimizing the chip’s spatial footprint. To optimize these advancements, appropriate edge termination designs for NiO/β-Ga 2 O 3 integration are crucial to achieve a high-power figure of merit (FOM) for power electronic devices, defined as (V B ) 2 /R ON where V B represents the breakdown voltage and R ON is the on-state resistance. Potential applications encompass EV charging, motor control, grid-scale power switching, and possibly for high-power RF amplifiers. Despite extensive research on current transport mechanisms, material selection for field plates, and the impact of field mitigation methods, challenges persist. The Ga 2 O 3 surfaces’ sensitivity to ion-induced damage poses a dilemma for rectifying contacts. Minimizing ion-induced damage during NiO p-layer deposition and optimizing field plate structures is crucial. Another focus is achieving thicker, lower-doped drift regions while maintaining low background carrier concentration. In this study, we provide structure design strategies for the devices with new highest V B and FOM. We find the experimental breakdown field of Ga 2 O 3 in current material is in the range 8–9 MV.cm −1 .