Structural and electrical analysis of the atomic layer deposition of HfO₂/n-In_0.53Ga_0.47 As capacitors with and without an Al₂O₃ interface control layer

High mobility III-V substrates with high- k oxides are required for device scaling without loss of channel mobility. Interest has focused on the self-cleaning effect on selected III-V substrates during atomic layer deposition of Al₂O₃. A thin (∼1 nm) Al₂O ₃interface control layer is deposited on In_0.53Ga _0.47 As prior to HfO₂ growth, providing the benefit of self-cleaning and improving the interface quality by reducing interface state defect densities by ∼50% while maintaining scaling trends. Significant reductions in leakage current density and increased breakdown voltage are found, indicative of a band structure improvement due to the reduction/removal of the In_0.53Ga_0.47 As native oxides.