Nanoindentation combined with scanning force microscope for characterization of mechanical properties of carbon nitride thin films

Scanning force microscope (SFM) imaging of the residual indent, in conjunction with the nanoindentation results, provides a better understanding of the response of a material to indentation at small scales. The true residual contact area directly measured from the SFM images can subsequently be used to recalculate the hardness of the material measured by nanoindentation more accurately. In this study, nanoindentation with SFM has been used to investigate the mechanical properties of thin CN films deposited by RF magnetron sputtering on silicon (1 0 0) substrates. Hardness was determined at different loads and depths from nanoindentation using the Oliver and Pharr method. The indents were imaged using SFM and true residual contact areas as well as hardness values were determined. Residual indentation depths from SFM and from nanoindentation were in agreement and hardness values obtained by SFM agreed with the hardness measured by the Oliver and Pharr method.