Residual stress in PZT thin films prepared by pulsed laser deposition

In this investigation, ferroelectric thin films Pb(ZrxTi1−x)O3(PZT) with x=0.58 were deposited on Pt/Ti/Si(001) by pulsed laser deposition (PLD). The residual stresses in PZT thin films were measured by an X-ray diffractometer (XRD) and indentation fracture method. In the indentation fracture method, the surface crack model and half-penny crack model were adopted. For PZT thin films with thickness of 0.05 μm, 0.5 μm and 1.0 μm, the residual stresses determined by a half-penny crack model were −74.73 MPa, −22.86 MPa and −14.74 MPa and those measured by XRD method were −57.6 MPa, −48.5 MPa and −25.6 MPa, respectively. The residual stresses determined by a half-penny crack model were closer to the results measured by XRD. A theoretical model is proposed to predict the residual stress in PZT thin film and the analytical results are essentially consistent with the experimental results. The effect of residual stress on piezoelectric properties is also discussed. The good ferroelectrics behaviors were demonstrated (Pr=22–35 μC cm−2, Ec=25–315 kV cm−1) by the hysteresis loops.