Electrical Characterization of Ferroelectric Pb(Zr, Ti)O3 Thin Films Deposited on Pt-Coated RuO2 Electrodes

Abstract

Ferroelectric Pb(Zr, Ti)O3 [PZT] thin films deposited on Pt-coated RuO2 electrodes are found to have concurrent advantages in both fatigue and leakage current characteristics. Perovskite phase of PZT having a random orientation was obtained on as-deposited and Pt-coated RuO2 bottom electrodes and the crystallinity increased slightly when the PZT films were deposited on Pt-coated RuO2. PZT films with hillock-free and fine-grained microstructures resulted in all the cases. The PZT films on hybrid electrodes (Pt/RuO2) showed a typical P–E hysteresis loop. PZT films in all the cases did not exhibit fatigue until over 1010 switchings regardless of the bottom electrodes. The asymmetric I–V curve of a PZT thin film on Pt/RuO2 exhibited the Schottky behavior, which indicates that blocking contact is formed at the interface between PZT films and hybrid electrodes. The leakage current density of the PZT thin films on as-deposited and 30-nm-thick Pt-coated RuO2 at 75 kV/cm was 4.73×10-6 and 9.55×10-7 A/cm2, respectively.