Microstress relaxation effect of Pb(Zr0.52Ti0.48)O3 films with thicknesses for micro/nanopiezoelectric device

In this study, we analyzed the microstress of Pb(Zr0.52Ti0.48)O3 (PZT) films using Raman spectrum and the macrostress using the wafer curvature method. Based on the stress analysis, we also determined the relationship between the residual stress and piezoelectric properties. We found that a thickness of 1 μm was critical since the stress relaxation starts due to surface roughening. Similarly, the film thickness dependence of the piezoelectric coefficient had saturation values around 1 μm, where the preferred orientation started to change from (111) to (110), indicating that the piezoelectric response was related to the stress relaxation with a preferred orientation change.