Prediction and identification of point defect fingerprints in X-ray photoelectron spectra of TiNx with 1.18 ≤ x ≤ 1.37
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Article in Periodical |
| Magazine / Source | MATERIALS & DESIGN |
| MU Faculty or unit | |
| Citation | |
| web | https://doi.org/10.1016/j.matdes.2025.114752 |
| Doi | https://doi.org/10.1016/j.matdes.2025.114752 |
| Keywords | TiN; Point defects; XPS; Vacancy quantification; N 1s and Ti2p binding energies; DFT |
| Description | We investigate the effect of selected N and Ti point defects in B1 TiN on N 1s and Ti 2p3/2 binding energies (BE) through experiments and ab initio calculations. X-ray photoelectron spectroscopy (XPS) measurements of TiNx films with 1.18 ? x ? 1.37 reveal additional N 1s spectral components at lower binding energies. Ab initio calculations predict that these components are caused by either Ti vacancies, which induce an N 1s BE shift of -0.54 eV in their first N neighbors, and/or N tetrahedral interstitials, which have their N 1s BE shifted by-1.18 eV and shift the BE of their first N neighbors by -0.53 eV. However, based on ab initio data the tetrahedral N interstitial is estimated to be unstable at room temperature. We, therefore, unambiguously attribute the N 1s spectral components at lower BE in Ti-deficient TiNx thin films to the presence of Ti vacancies. Furthermore, it is demonstrated that the vacancy concentration in Al-capped Ti-deficient TiNx can be quantified with the proposed correlative method based on measured and predicted BE data. Our work highlights the potential of ab initio-guided XPS measurements for detecting and quantifying point defects in B1 TiNx. |
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