Chemical Bonding, Interfaces, and Defects in Hafnium Oxide∕Germanium Oxynitride Gate Stacks on Ge(100)

Correlations among interface properties and chemical bonding characteristics in metal–insulator–semiconductor stacks were investigated using in situ remote nitridation of the Ge(100) surface prior to atomic layer deposition. Ultrathin , thermally stable, and aqueous etch-resistant interface layers that exhibited Ge core-level photoelectron spectra similar to stoichiometric were synthesized. To evaluate interface defects, the density of interface states was extracted by the conductance method across the bandgap. Forming gas annealed (FGA) samples exhibited substantially lower than did high-vacuum-annealed and inert gas anneal samples . Germanium core-level photoelectron spectra from similar FGA-treated samples detected out-diffusion of germanium oxide to the film surface and apparent modification of chemical bonding at the interface which is related to the reduced .