Electronic structure and defects of high dielectric constant gate oxide La2Hf2O7

Abstract

The electronic structure of the high dielectric constant oxide La2Hf2O7 and its oxygen vacancies have been calculated. The lowest conduction band is localized on Hf d states and the next is localized on Hf and La d states. The charge density on the O vacancy surrounded by 4 La ions, when in clusters, can become localized on next neighbor Hf ions. It may help create interface dipoles to modify effective work functions.