The effect of electrode material on the electrical conduction of metal-Pb(Zr0.53Ti0.47)O3-metal thin film capacitors

The electrical conduction of metal-PZT-metal thin-film capacitors depends on the electrode material due to the different magnitudes of the work functions. In this work, Au/PZT/Pt and Pt/PZT/Pt capacitors were fabricated and their electrical properties compared. At the low temperature range of 300-375 K, the electrical conduction of Au/PZT/Pt capacitor is space-charge-limited current (SCLC), whereas Pt/PZT/Pt capacitor shows ohmic conduction at low field (<0.55 MV/cm) and Frenkel-Poole emission at higher fields (⩾0.55 MV/cm). The current level of Au/PZT/Pt is much lower than that of Pt/PZT/Pt at low field (<0.4 MV/cm) due to the larger barrier height for holes of Au/PZT. At high temperatures (375-450 K), the conduction mechanism of Au/PZT/Pt capacitor changes to Schottky emission, whereas that of Pt/PZT/Pt capacitor remains the same as in low temperatures of 300-375 K. The energy band diagrams of the Au/PZT/Pt and Pt/PZT/Pt systems are constructed to explain the different current-voltage characteristics.