Stability and degradation of isolation and surface in Ga2O3 devices

Within this paper, we report the first study on the reliability of isolation structures and surfaces for the gallium oxide material system. Even though insulation by Mg-doping implantation and diffusion is found to provide a stable electrical isolation at increasing temperature, a significant thermally-activated leakage flows through surface states. The vertical bulk material does provide a better stability of the isolation over stress time, but withstands a lower level of stress compared with the surface and the lateral structure, possibly due to the charge trapping at the surface of the latter that mitigates the peak electric field.