Investigation of interfacial structures of oxides on GaAs substrates by HRTEM

The present study shows the structural properties of Al₂O₃, SiO₂, Ga₂O₃ and (Ga,Gd)₂O₃ on GaAs substrates. Studies using high-resolution transmission electron microscopy on the oxide-GaAs interface indicate some atomic registry between the oxide and GaAs during the initial growth. ACF and C-V measurements further illustrated the phenomenon of this transition layer, which plays a key role in the excellent interface quality offered by the (Ga,Gd)₂O₃/GaAs system, rendering the latter a better choice than systems based upon the other oxide materials.