X-ray absorption spectra for transition metal high-κ dielectrics: Final state differences for intra- and inter-atomic transitions

The electronic structure of the high-k gate dielectrics, TiO ₂, ZrO ₂, and HfO ₂ was investigated using x-ray absorption spectroscopy and high-resolution electron microscopy (HREM). Intra-atomic and inter-atomic transitions were found to have many type of qualitative and quantitative differences. The optical band gap differences for TiO ₂, ZrO ₂, and HfO ₂ led to the differences between the spectral peak energies of the lowest d*-features in the O K ₁ spectra. TM oxides were found to have applications in advanced Si devices in the form of high-k dielectrics, indicated by the conduction band offset energies between Si and the respective dielectrics, and the optical band gaps.