TAILORING HIGH-K/SILICON INTERFACE FOR NANOELECTRONICS APPLICATIONS

摘要

Electronic and material properties of ZrO_2 and HfO_2 films on silicon were investigated using first principle simulations, x-ray photoelectron spectroscopy (XPS)), extended x-ray absorption fine structure analysis (EXAFS), and electrical device measurements. The calculated conduction band offsets ranged from 0.64-1.02 eV, in agreement with the XPS measurements (0.88+-0.2 eV). The EXAFS analysis confirmed the chemical coordination of ZrO_2 and HfO_2 thin films to that of their monoclinic phases. Capacitance-voltage and current-voltage measurements yield dielectric constants ranged from 18-23 depending on the processing conditions and leakage currents a few orders of magnitude lower than that of SiO_2 films having the same equivalent oxide thickness.