Study of GaAs oxidation in the low-current Townsend discharge

An anodic oxidation of GaAs substrates in a non-self-sustained low-current dc Townsend discharge is investigated. The process is carried out at the room temperature in a three-electrode microreactor filled by 98%Ar + 2%O2 gas mixture. Investigation of the oxidation kinetics indicates that the formed oxide is characterized by a high resistivity, ρ ∼ 1011 Ω·cm. It is demonstrated the application of the method for formation of oxide films with dimensions of tens of microns, which thickness is on the nanometer scale. Examination of the “GaAs substrate - oxide layer” interface using the high resolution transmission electron microscopy has revealed that the oxide is characterized by the amorphous structure.