AVS 47th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuA

Paper TF-TuA3
Anomalous Plastic and Elastic Behaviors of Sputter-deposited TiN with 10 or 20 Inserted Thin Al Layers Evaluated by Nanoindentation

Tuesday, October 3, 2000, 2:40 pm, Room 203

Session: Mechanical Properties of Thin Films
Presenter: E. Kusano, Kanazawa Institute of Technology, Japan
Authors: E. Kusano, Kanazawa Institute of Technology, Japan
N. Kikuchi, Kanazawa Institute of Technology, Japan
K. Tsuda, Kanazawa Institute of Technology, Japan
H. Nanto, Kanazawa Institute of Technology, Japan
A. Kinbara, Kanazawa Institute of Technology, Japan
Correspondent: Click to Email
The hardness enhancement observed for multilayered thin films results from the specialized mechanical properties of the interface region. In this paper, effects of thin Al layers inserted into the TiN matrix thin film on mechanical properties of the coating have been investigated in order to discuss a role of the interface regions made by the Al thin layer insertion. Thin films of TiN with Al thin layers have been deposited by dc magnetron sputtering. The total TiN thickness was kept at 500 nm for all prepared samples. The number of thin Al layers inserted was varied from 2 to 20 for the total Al thickness of 100 to 500 nm. The top layer of the coating was TiN for all sample coatings. Film hardness of prepared samples was estimated by nanoindentation. From a load-unload curve of the nanoindentation, energies consumed to induce plastic deformation and elastic deformation were estimated. A hardness of thin films with 20 Al layers decreased from 11 GPa to 8GPa when the total Al layer thickness increased from 100 to 500 nm. For a constant total Al layer thickness, the film with 20 Al layers yielded higher hardnesses. The film with 20 Al layers with a layer thickness of 5 nm was harder than the monolithic TiN film. While the energy used for plastic deformation during nanoindentation increased with the total Al layer thickness, the energy used for elastic deformation remained constant. Further, the dissipated energy decreased with increasing the number of Al layers inserted. These results obtained by nanoindentation measurement imply that the film becomes more elastic with increasing the number of Al layers inserted. A high microhardness obtained for a film with Al layer thickness of 5nm emphasizes a unique effect of thin Al layers or interface regions on mechanical properties of the coating.