P2J-1 Love-Wave Characterization Platform for Micro and Nano Processed Thin Films

Acoustic wave sensors uses more and more often micro and nano-structured thin film new materials (e.g. as sensitive layer). This lead to an increasing need for materials viscoelastic properties characterization. A new characterization method is proposed here using Love-wave platforms and allowing the material properties characterization directly with the sensor platform. A Love-wave device consists in a multilayer structure with a piezoelectric substrate, a guiding layer and, for chemical detections, a sensitive layer able to trap chemical species. Sensitive and guiding layers involve thin films organic and inorganic materials in which a 100 MHz Love-wave propagates during sensor operation. Materials are then excited at high frequency and mechanical properties are affected by the wave propagation. The characterization method determines material layer density and shear modulus by fitting simulation results to experimental measurements. First results concern the characterization of Love-wave SiO₂ guiding layer and demonstrate that using characterized SiO₂ density and shear modulus allows to simulate accurately the wave phase velocity of Love-wave devices with different SiO₂ guiding layer thicknesses