Effect of different electrode on the dielectric properties of lanthanum-doped lead titanate ferroelectric thin films

Lanthanum-doped lead titanate [(Pb0.9La0.1)TiO3, PLT10] ferroelectric thin films were grown on Si (100) and Pt/Ti/SiO2/Si(100) substrates by RF magnetron sputtering. The crystalline properties of PLT10 films were studied by X-ray diffraction (XRD). Photolithographic technique was applied to fabricate the interdigital electrodes of PLT10 thin films on Si(100) substrates. The dielectric properties of PLT10 thin films with different electrode were measured. At room temperature and 1 kHz testing frequency, the dielectric constant of PLT10 thin film with interdigital electrodes is 386. The dielectric constant of PLT10 thin film fabricated in the same technological conditions with parallel plate electrodes structure is 365, while the dielectric constant and loss of PLT10 thin film with interdigital electrodes decreased faster than those of the film with parallel plate electrodes with frequency increasing. This is because that more influences of interface state were introduced due to the interdigital electrode configuration.