Advanced high-k gate dielectric amorphous LaGdO3 gated metal-oxide-semiconductor devices with sub-nanometer equivalent oxide thickness

摘要

Careful selection of pulsed laser deposition conditions was executed to achieve sub-nanometer EOT (equivalent oxide thickness) in amorphous LaGdO3 based high-k/metal gate stacks. The lowest EOTs attained were ～5.4?? and 8.4?? with and without quantum mechanical correction, respectively. The electrical measurements yielded a high permittivity of 20.5?±?2.4, a thin bottom interfacial layer of thickness 4.5?±?1??, and interface (cm-2?eV-1) and fixed (cm-2) charge densities of ～1012. Analysis of temperature dependent leakage currents revealed that gate injection current was dominated by Schottky emission below 1.2?MV/cm and quantum mechanical tunneling above this field. The physical origin of substrate injection was found to be a combination of Schottky emission and trap assisted tunneling.