Effect of prebaking temperature on structure and ferroelectric properties of PZT thin films prepared by sol-gel method

The effect of prebaking temperature on the uniformity, crystal orientation, grain size and ferroelectric properties of the PZT thin films prepared by a sol-gel method on PbTiO₃/Pt/SiO₂/Si substrates was studied. The film prebaked at 200°C and annealed at 650°C showed relatively homogeneous surface morphology consisting of microcrystals with dispersed columnar crystal grains. It exhibited well-defined P-E hysteresis loops with P*r-Pr of 66 μC/cm² and a leakage current of 3.40 ×10^-5 A/cm². In contrast, the film prebaked at 500°C and annealed at 650°C showed a "rosette" structure consisting of large crystal grains and residual microcrystals containing pyrochlore. This film exhibited rather inferior ferroelectric properties and uneven depth profiles of the constituent elements. The degree of preferred crystal orientation for (111) planes was found to decrease with increasing prebaking temperature, whereas no change was observed for the degree of (100) preferred orientation.