Characterization of RF sputter-deposited ultra thin PZT films and its Interface with substrate

Lead Zirconate Titanate [Pb(Zr,Ti)O(3), PZT] thin films have been extensively studied due to their possible applications in ferroelectric and piezoelectric devices. This work deals with the synthesis and characterization of ultra thin PZT films of thickness similar to 100 nm deposited on Si/SiO(2)/TiO(2)/Pt(111) by RF Magnetron Sputtering under optimized deposition and post-annealing conditions. Various techniques like XRD, XPS, SIMS, SEM and TEM, have been employed to characterize the film nanostructure and the interface quality in the post-annealed films. Though the XRD results showed the formation of similar to 87 vol% perovskite phase with 111 orientation, the films failed to show good electrical and ferroelectric properties. In XPS study of annealed PZT films, Pb was found to exist in both oxidised and metallic states. Both SIMS depth profiling and STEM-EDX line profile results showed that there is an enrichment of Pb along the PZT/Pt interface. This suggests interdiffusion of the elements in the film during post-annealing. It is concluded that interdiffusion of the chemical species during annealing results in Pb enrichment at the film substrate interface. In addition, the presence of similar to 13% non-ferroelectric pyrochlore phase as well as some amount of Pb species present in metallic state further degrades the film quality