Comparative Investigation of NbN and Nb-Si-N films: Experiment and Theory

Abstract

NbN and Nb-Si-N films have been deposited by magnetron sputtering of the Nb and Si targets on silicon wafers at various powers supplied to the Nb target. The films have been investigated by an atomic force microscope, X-ray diffraction, X-ray photoelectron spectroscopy, nanoindentaion and microindentation. The NbN films were nanostructured, and the Nb-Si-N films represented an aggregation of δ-NbN x nanocrystallites embedded into the amorphous Si₃N₄ matrix (nc-δ-NbN x /a-Si₃N₄). The annealing of the films in vacuum showed that their intensive oxidation occurred at annealing temperature higher than 600°C. To explain the experimental results on the Nb-Si-N films, first-principles molecular dynamics simulations of the NbN(001)/Si₃N₄ heterostructures have been carried out.