Current conduction processes in high-κ Gd0.31Ga0.1O0.59/Ga2O3 gate dielectric stacks on GaAs

Current conduction processes in high-κ (κ=20.2) Gd0.31Ga0.1O0.59/Ga2O3 dielectric stacks grown on n-type GaAs by molecular beam epitaxy have been investigated. Metal-oxide-semiconductor capacitors have been characterized by current density (j) versus electric field (E) measurements at temperatures ranging from 90 to 450 K. For temperatures T⩽200 K, the high field (4.5⩽E⩽6.2 MV/cm) current is temperature independent and a Fowler–Nordheim tunneling slope of 1.75 eV3/2 is obtained. Frenkel–Poole emission is found to dominate at temperatures of 300 K and above at moderate electric fields (1.3⩽E⩽2.2 MV/cm). For Frenkel–Poole emission, a barrier height of 1.1 eV and a dynamic dielectric constant of 7.95 is derived from ln(j/E) vs 1/T and ln(j/E) vs E1/2 plots, respectively.