Effects of orientation on microstructure and mechanical properties of TiN/AlN superlattice films

Superlattice structure can significantly improve the hardness of the films without damaging the toughness. However, in TiN/AlN superlattice structure, the thickness of metastable c-AlN has a certain limit, which limits the improvement of hardness. We adjusted the orientation of the entire superlattice films under the same deposition parameters and observed that AlN has a thicker coherent thickness in the < 110 >-oriented TiN/AlN superlattice film relative to the < 100 > orientation through HRTEM, and the superlattice film reached a higher hardness peak value (similar to 38.6GPa) at the same time. This work provides a new implementation method to improve the mechanical properties of superlattice films. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

By adjusting the orientation of the entire superlattice films under the same deposition parameters, it was observed that AlN has a thicker coherent thickness in the <110>-oriented TiN/AlN superlattice film, leading to a higher hardness peak value of around 38.6GPa. This work provides a new implementation method to improve the mechanical properties of superlattice films.