Young's modulus measurement of a thin film from experimental nanoindentation performed on multilayer systems.

The nanoindentation technique is suitable for the characterization of the mechanical properties of thin films. However, for layers of a few hundred nanometers thick, the substrates as well as the underlying layers are mechanically involved and the measures are not connected in a simple manner to the properties of the thin film. The purpose of this study is to present an extension of the simple analytical model of Bec et al. in the case of a thin film deposited on a multilayer system. The multilayer model was applied to experimental results obtained by nanoindentation of a stack of layers of materials with significantly different Young's moduli (Au/Ti/SiO2 multilayer deposited on a single crystalline Si substrate), according to a precise methodology. The Young's modulus calculated for gold with the multilayer model is 81 GPa, which is consistent with the literature (EAu = 80 GPa). The results show that the developed model is appropriate to determine the Young's modulus of a thin film deposited on a multilayer system.