Thickness effects on structures and electrical properties of lead zirconate titanate thick films

PbZr0.52Ti0.48O3 thick films with thickness of 1–6 μm have been prepared by a polymer-assisted MOD process. The polymer, poly(vinyl acetate) (PVAc) was introduced into PZT precursor solutions. The grain size increased from 30 nm to 100 nm with an increase of the additive amount of PVAc. Meanwhile, the grains grew larger (in a range of 100–500 nm) and the surface of the films became rougher with increasing film thickness. This promotes the structural relaxation and prevents cracking formation. The critical thickness at which the film begins to crack increases significantly. The dielectric constant and remanent polarization (Pr) increased from 1070 to 1490 and from 36.1 μC/cm2 to 52.4 μC/cm2, respectively, and the coercive field (Ec) decreased from 57.3 kV/cm to 41.3 kV/cm as the film thickness increased from 0.95 μm to 6.02 μm. PZT thick films prepared in this study are promising materials for MEMS applications.