Studies of BaTiO3 thin films on different bottom electrode

BaTiO3 (BT) thin films were prepared on Pt/Ti/SiO2/Si and Ru/Ti/SiO2/Si substrates by a modified sol-gel technique. The microstructure of the films was characterized by atomic force microscopy (AFM), X-ray diffraction (XRD) and Raman spectroscopy. The results showed that BT thin films crystallized with perovskite structure. Compared to BT film on Pt/Ti/SiO2/Si substrate, BT thin film deposited on Ru electrode has similar dielectric constant, while it has higher dielectric loss. C–E curve for BT film on Pt/Ti/SiO2/Si was more symmetrical around zero-bias field than C–E curve for BT film on Ru/Ti/SiO2/Si substrate. The tunability was 52.02% for BT film on Pt electrode, which was 33.42% on Ru electrode, at 275 kV/cm and room temperature. The leakage current density of BT on Pt electrode was about an order of magnitude lower than BT film on Ru electrode at the applied electrical field below 150 kV/cm. The leakage conduction mechanism was investigated.