Modeling of metastable phase formation diagrams for sputtered thin films
Coating and Surface Technology
Final Report Abstract
The major objective of this project was to develop a model to predict metastable phase formation of nitride thin films considering kinetic effects, based on one combinatorial magnetron sputtering experiment, CALPHAD, and ab initio calculations. The model was validated for the application relevant growth temperature range of 100 °C to 550 °C. Experimental data from magnetron sputtered Ti1-xAlxN thin films are in good agreement with the model, which describes the effect of composition, deposition temperature, and kinetic factors on the metastable phase formation of Ti1-xAlxN systematically. Furthermore, compared to the lowest experimentally reported xmax value of 0.40, the here predicted xmax value is 0.42 consistent with the experiment. The here reported model allows for the prediction of the experimentally reported xmax range of 0.42 < xmax < 0.50, which was previously unobtainable by energetics-based models. This significant extension of the predicted critical solubility range is enabled by taking the effect of the activation energy for surface diffusion and the critical diffusion distance on the metastable phase formation into account. Hence, all goals raised in this project have been reached and the obtained data were communicated in a high-profile international journal (Acta Materialia).
Publications
- Modeling of metastable phase formation for sputtered Ti1-xAlxN thin films, Acta Materialia 165 (2019) 615-625
S. Liu, K. Chang, S. Mráz, X. Chen, M. Hans, D. Music, D. Primetzhofer, J.M. Schneider
(See online at https://doi.org/10.1016/j.actamat.2018.12.004)
