Current conduction mechanisms of RF-Magnetron sputtered Y2O3 gate oxide on gallium nitride

•Current conduction mechanisms are investigated for Y2O3/GaN structure.•Change of conduction mechanisms is dependent on annealing temperature.•The dominance of conduction mechanisms are influenced by electric field.•Measurement temperature is affecting the governing conduction mechanisms.

Current conduction mechanisms through as-deposited and post-deposition annealed (200–800 °C) RF-magnetron sputtered Y2O3 gate oxides on n-type GaN have been systematically investigated with current–voltage measurements at temperature in the range of 25–175 °C. The possible current conduction mechanisms that govern the leakage current of Y2O3/GaN metal-oxide-semiconductor test structure are space-charge-limited conduction, Schottky emission, Poole–Frenkel emission, and Fowler-Nordheim tunneling. The dominance of these conduction mechanisms is depending on applied electric field and measurement temperatures.