Published online by Cambridge University Press: 01 February 2011
Substrate effects continue to be the key issue in interrogating thin films by nanoindentation. In this study, we studies amorphous thin films of several different materials deposited onto a silicon wafer. These materials span from being considerable softer than the substrate to films significantly harder than the substrate. The thin film Young's modulus Ef was measured with a MTS Nanoindenter XP system using the continuous stiffness measurement (CSM). The so-called “flat region” was observed in the early stage of nearly every CSM modulus-displacement curve for all materials studied. The depth of this region (hcr) was found to vary with the material. Based on the experimental data, we were able to modify the Doerner & Nix model for thin film indentation on a substrate, particularly their parameter alpha (α). The modified relation was found to be adept at closely matching all experimental data collected, which spanned both soft films on hard substrates and hard films on soft substrates.