Field-Plated NiO/Ga2O3 p-n Heterojunction Power Diodes With High-Temperature Thermal Stability and Near Unity Ideality Factors

In this work, vertical NiO/Ga
₂
O
₃
heterojunction diodes (HJDs) integrated with SiN
_x
/Al
₂
O
₃
double-layered insulating field plate (FP) structures have been demonstrated. With the additional post-annealing, the resultant diode exhibits a decreased differential specific on-resistance (
$\text{R}_{\mathrm{ on,sp}}$
) of 5.4
$\text{m}\boldsymbol{\Omega } \cdot $
cm
²
and an enhanced breakdown voltage (BV) of 1036 V. The improved performance is attributed by the combination of the FP-suppressed crowding electric field at the device edge and the reduced trap density at the NiO/Ga
₂
O
₃
interface. In particular, the near-unity ideality factor has been achieved for this p-n HJD at an elevated temperature of 275 °C, indicating that the diffusion current is dominated. The high-temperature operation capability is owing to the quality improvement of NiO/Ga
₂
O
₃
interface, where the Shockley-Read-Hall (SRH) recombination mediated by deep-level defects within the depletion region is thus suppressed.