The performance of Zr as barrier layer for Pt bottom electrodes in Pb(Zr,Ti)O3 thin film capacitors

The performance of Zr as adhesion/barrier layer for Pt bottom electrodes with the Pt deposited at different temperatures and its effect on the properties of Pb(Zr0.52, Ti0.48)O3 (PZT) thin films deposited by radio-frequency magnetron sputtering and crystallized either in the furnace or by rapid thermal annealing was investigated. Platinum deposition temperatures and annealing method affected only slightly the (100) PZT orientation. The surface morphology of the films was strongly influenced by the Pt deposition temperature: when Pt was made at low temperatures, its grain size was small and the surface of the PZT made over it was smooth, whereas for Pt high deposition temperatures, the grain size was bigger and the PZT surface was rough. The best ferroelectric properties (Pr=22 μC/cm2 for Ec=110 kV/cm and Pr=24 μC/cm2 for Ec=95 kV/cm) and the lowest leakage currents (7.2×10−8 A/cm2 and 8.2×10−8 A/cm2 for a 125 kV/cm field) were obtained for the PZT films crystallized in the furnace with Pt deposited at room temperature and 500 °C, respectively.