Structural and electrical analysis of the atomic layer deposition of HfO_2-In_(0.53)Ga_(0.47)As capacitors with and without an Al_2O_3 interface control layer

摘要

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 Al_2O_3. A thin (～1 nm) Al_2O_3 interface control layer is deposited on In-(0.53)Ga_(0.47)As prior to HfO_2 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_(0.53)Ga_(0.47)As native oxides.