Micromechanics predictions of effective elastic, piezoelectric and dielectric properties of composite piezoelectric films

Abstract Knowledge of the effective elastic, piezoelectric and dielectric properties facilitates the design of radio frequency devices, for example film bulk acoustic resonators (FBARs). Based on the Reuss model and Eshelby–Mori–Tanaka micromechanics theory, this paper predicts the effective properties of bilayer composite piezoelectric film consisting of AlN film and vertical compound ScAlN film. The evaluated material coefficients and original material parameters are substituted into the FEM simulation to investigate the performance of FBARs, respectively. The consistent resonant frequencies of FBARs demonstrate the accuracy of Reuss model in calculating the effective parameters of bilayer composite piezoelectric film.