Analysis of titanium species in titanium oxynitride films prepared by plasma enhanced atomic layer deposition

A comparative study of thin titanium oxynitride (TiOxNy) films prepared by plasma enhanced atomic layer deposition using tetrakis(dimethylamino)titanium (TDMAT) and N2 plasma as well as titanium(IV)isopropoxide and NH3 plasma is reported. The comparison is based on the combination of Ti2p core level and valence band spectroscopy and current-voltage measurements. The TDMAT/N2 process delivers generally higher fractions of TiN and TiON within the Ti2p spectra of the films and stronger photoemissions within the bandgap as resolved in detail by high energy resolution synchrotron-based spectroscopy. In particular, it is shown that higher TiN contributions and in-gap emission intensities correlate strongly with increased leakage currents within the films and might be modified by the process parameters and precursor selection. •Titanium oxynitride PEALD processes using TDMAT/N2 or TTIP/NH3 are compared.•Influence of ALD parameters on film composition and leakage current is shown.•Strong photo-emissions within the bandgap are observed in the valence band spectra.•TiN bonded nitrogen and in-gap states correlate strongly with leakage current.•TDMAT/N2 process delivers higher TiN and in-gap state contributions.