The characterization of titanium nitride by x-ray photoelectron spectroscopy and Rutherford backscattering

Abstract

X-ray photoelectron spectroscopy (XPS) spectra have been obtained for TiNx, with x=0.25, 0.50, and 1.0, as determined by Rutherford backscattering (RBS) analyses, and with no detectable oxygen content. We find the shape of the Ti 2p transition to be strongly dependent upon the nitrogen content, and interpret the spectrum as a mixture of Ti and TiN. TiN1.0 samples with varying oxygen content were also examined, and the oxygen content serves to increase the background step in the Ti 2p transition. Angle resolved measurements indicate that the inelastic scattering due to oxygen is superimposed over an intrinsic satellite structure in the Ti 2p transition. Atom ratios, N/Ti, cannot be accurately determined by XPS without standardization. The binding energy of the Ti 2p3/2 transition occurs at 454.5 eV and the N 1s transition occurs at 396.7 eV. The oxygen that is present in TiN at concentrations up to 12 at. % is most likely bound to Ti as TiO rather than TiO2. Valence band measurements agree well with previous reports.