Structural and dielectric characterization of the (Ba1−xSrx)(Ti0.9Sn0.1)O3 thin films deposited on Pt/Ti/SiO2/Si substrate by radio frequency magnetron sputtering

Abstract

( Ba 1−x Sr x )( Ti 0.9 Sn 0.1 ) O 3 (BSxTS) thin films prepared by rf magnetron sputtering have been characterized as a function of temperature, applied voltage, and electric field. The BSxTS thin films have been confirmed with x-ray diffraction and electron diffraction analysis. The BSxTS thin films show a strong (111) preferred orientation for Sr content 0.1≦x≦0.3. Grain size increases with increasing deposition temperature and is correlated to high dielectric constants. Leakage current density at 1 kV/cm varies from below 10−7 to mid 10−9 A/cm2 for the O2/(O2+Ar) ratio varying from 5/(5+5) to 1/(1+9). A large and clear hysteresis shows ferroelectricity at 25 °C for all BSxTS thin films. The remnant polarization increases with increasing Sr content, which is preseemably caused by the lattice mismatch between BSxTS thin films and Pt layers.