Preparation and characterization of SrTiO3/BaTiO3 thin multilayer films deposited on Pt/Ti/SiO2/Si substrate by radio frequency magnetron sputtering

SrTiO3/BaTiO3 thin films with multilayer structure were deposited on Pt/Ti/SiO2/Si substrates by a double target radio frequency (RF) magnetron sputtering at 500 °C. The structure and properties of the SrTiO3/BaTiO3 thin multilayers have been evaluated by X-ray diffraction (XRD), Auger electron spectrometry (AES), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), electron diffraction (ED) and polarization-electric field hysteresis loop. The XRD result reveals that the SrTiO3/BaTiO3 thin multilayers with the designed modulation have been accomplished. The lattice strain increases with layer number. According to AES analysis and morphology observation, a discrete interlayer exists at a position between the interface of Pt electrode and SrTiO3. The remanent polarization (Pr) and coercive field (Ec) of SrTiO3/BaTiO3 thin multilayer are 3.0 μC/cm2 and 20.0 kV/cm, respectively. In comparison with BaTiO3, the device containing dual layers of SrTiO3/BaTiO3 possesses higher Ec but lower Pr.