Thickness dependence of structural and piezoelectric properties of epitaxial $Pb(Zr0.52Ti0.48)O3$ films on Si and $SrTiO3$ substrates

We report the structural and longitudinal piezoelectric responses $(d33)$ of epitaxial $Pb(Zr0.52Ti0.48)O3$ (PZT) films on (001) $SrTiO3$ and Si substrates in the thickness range of $40nm–4μm$⁠. With increasing film thickness the tetragonality of PZT was reduced. The increase in $d33$ value with increasing film thicknesses was attributed to the reduction of substrate constraints and softening of PZT due to reduced tetragonality. The $d33$ values of PZT films on Si substrates $(∼330pm∕V)$ are higher than those on $SrTiO3$ substrates $(∼200pm∕V)$⁠. The epitaxial PZT films on silicon will lead to the fabrication of high performance piezoelectric microelectromechanical devices.