Effect of Zr/Ti stoichiometry ratio on the ferroelectric properties of sol-gel derived PZT films

A series of sol-gel-derived PZT (lead zirconate titanate) films with Zr:Ti ratios of 100:0, 94:6, 80:20, 65:35, 53:47, 35:65, 20:80, and 0:100 was prepared on platinized Si wafers. The precursor chemistries were based on lead acetate and Zr/Ti alkoxides containing the appropriate amounts of cations in the required stoichiometries. Excess PbO was incorporated to compensate for PbO loss during processing. Films were fired to 700 degrees C where they were all single-phase perovskite as determined by XRD (X-ray diffraction). Microlithography was performed to obtain Pt-PZT-Pt monolithic capacitors with 130- mu m by 130- mu m electrode pads. The ferroelectric properties on these pads were measured along with the leakage characteristics. The dielectric and ferroelectric properties of the PZT films were found to be highly dependent on composition and processing conditions.< >