Determination of Density and Young´s Modulus of Atomic Layer Deposited Thin Films by Resonant Frequency Measurements of Optically Excited Nanocantilevers

We report on a methodology for simultaneous determination of the Young´s modulus and density of ultrathin films from a resonance experiment. The approach is based on an interferometric detection of the in-plane and out-of-plane resonant responses of an optically excited single crystal Si nanocantilever prior and after Atomic Layer Deposition (ALD) of a thin film. The frequencies shifts were measured at the same structure reducing sensitivity to scattering in geometric parameters and clamping compliances. Experimental results obtained for Al₂O₃ (alumina) and HfO₂ (hafnia) were consistent with the model predictions and the data available in literature.