Exploring current conduction mechanisms in 6 MeV $\text{Si}^{3+}$ ion irradiated Au/SiO2/beta-Ga2O3 metal-oxide-semiconductor devices

Wide bandgap and cost-effective features place Ga
2
O
3
as a viable candidate for various power electronic devices. Au/SiO
2
/beta-Ga
2
O
3
metal-oxide-semiconductor devices are tested for radiation response with 6 MeV
$\text{Si}^{3+}$
ions. The leakage current density is found to increase from
$8.6\times 10^{-5} \mathrm{A}/\text{cm}^{2}$
(for pristine device) to
$9.8\times 10^{-4}\mathrm{A}/\text{cm}^{2}$
(at
$5\times 10^{16}\ \text{ions}/\text{cm}^{2}$
fluence) at −10 V. Various current conduction mechanisms are explored under gate and substrate injection in these devices. Under gate injection, the direct tunneling dominates at low voltage regime of 0 to −3 V at all fluences due to low SiO
2
thickness
$(\sim 10\ \text{nm})$
. The Poole-Frenkel emission is quite dominant at
$5\times 10^{16}\text{ions}/\text{cm}^{2}$
attributed to the increased number of trap states in SiO
2
, and the estimated shallow trap depth is 0.4 (pristine) to 0.2 eV (highest fluence) from the conduction band edge. The barrier height (BH) of SiO
2
/beta-Ga
2
O
3
interface estimated from the Fowler-Nordheim tunneling under substrate injection is 2.52 eV for the pristine device and the BH is found to decrease to 1.83 eV at
$1\times 10^{16}\ \text{ions}/\text{cm}^{2}$
fluence.