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Measurement of mechanical properties of thin films by nanocompression
Kuběna, Ivo ; Kruml, Tomáš ; Hutař, Pavel ; Boháč, Petr ; Stranyánek, Martin ; Čtvrtlík, Radim ; Pánek, P. ; Vystavěl, T.
Mechanical properties of thin films are not easy to be measured. This is particularly true in the case of plastic properties as the yield point, the work hardening rate or the ultimate stress. Nevertheless, such parameters are needed e.g. in the design of integrated circuits where the thermal stresses may lead to mechanical failure of the component. We applied two modern experimental facilities, the focused ion beam and the nanoindentation for exact measurement of plastic properties of a Al-1.5%Cu thin film prepared by PVD, used for electrical connection of integrated circuits. By FIB milling, cylindrical specimens were prepared. The height of the specimens was equal to the film thickness (2 m) and their diameter was about 1.3 m. These specimens were subjected to the compressive loading using the nanoindenter equipped by a flat punch. Stress-strain curves of the film were obtained rather precisely.
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