Demonstration of the p-GaN Gate HEMT with Crystalline GaOx/GaOxN1-xPassivation

We investigate GaN HEMT devices with a crystalline
$\text{GaO}_{\mathrm{x}}/\text{GaO}_{\mathrm{x}}\mathrm{N}_{1-\mathrm{x}}$
passivation layer. The p-GaN layer, subjected to oxygen plasma treatment (OPT) and post-annealing process (PA), transforms into a
$\text{GaO}_{\mathrm{x}}/\text{GaO}_{\mathrm{x}}\mathrm{N}_{1-\mathrm{x}}$
layer, leading to the recovery of the depleted two-dimensional electron gas (2DEG) underneath. The p-GaN HEMTs with
$\text{GaO}_{\mathrm{x}}/\text{GaO}_{\mathrm{x}}\mathrm{N}_{1-\mathrm{x}}$
passivation exhibit satisfactory characteristics at a PA temperature of 450°C with an
$I_{\text{ON}}/I_{\text{OFF}}$
ratio
$> 10^{8}$
. Additionally, the OFF-state breakdown voltage reached 1018 V for a gate-to-drain separation of 15 μm. The results indicate the merits of employing
$\text{GaO}_{\mathrm{x}}/\text{GaO}_{\mathrm{x}}\mathrm{N}_{1- \mathrm{x}}$
passivation to realize the p-GaN HEMT.