Effects of rapid thermal annealing on nucleation, growth, and properties of lead zirconate titanate films

The nucleation and growth behavior of sol-gel-derived lead zirconate titanate (PZT) films was investigated at different rapid thermal annealing (RTA) processes. The effects of RTA on PZT film surface morphology, crystal orientation, residual stress, and properties were also studied and are discussed. PZT nucleation and growth behavior were found to be more sensitive to heating rate than to hold time during RTA. Higher heating rates were preferred for uniform PZT nucleation and grain growth, which resulted in dense microstructures, smooth surfaces, and better film ferroelectric properties. Lower heating rates led to strong PZT (100) orientation, better film piezoelectric properties, and low residual stress, but at the risk of film cracks caused by arbitrarily distributed large crystallites with diameters of ~300 nm among crystallites with diameters of ~30 nm. Furthermore, the residual stress of the PZT film was found to be effectively reduced by extending the hold time.