The influence of SrTiO3 buffer layer on ferroelectric properties of Al-doped BaTiO3 thin films

Abstract

Fabrication of Al0.01Ba0.99TiO3 (Al-BTO) thin films on SrTiO3/MgO/TiO2/SiO2/Si (STO/MgO) and MgO/TiO2/SiO2/Si (MgO) substrates were comparatively prepared using pulsed laser deposition (PLD). The structures of the prepared thin films were studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The SrTiO3 buffer layer between Al-BTO thin film and MgO substrate enhanced the ferroelectric, electrical properties. Moreover, the P-E loops showed a dramatic enhancement in the polarization values from 18 μC/cm2 at 600 kV/cm to 52 μC/cm2 at 780 kV/cm for Al-BTO thin films on SrTiO3/MgO and MgO substrates, respectively. In addition, the dielectric SrTiO3 buffer layer decreased the leakage current from 3 × 10−3 to 12 × 10−6 A/cm2 and increased breakdown electric field from 10 to 30 kV/cm. The electric properties revealed that, the dielectric SrTiO3 buffer layer also decreased the conductivity, mobility and carrier concentrations. The data of Al-BTO thin films on SrTiO3/MgO substrate exhibited remarkably adjusted polarization and leakage current indicating a good ferroelectric property for non-volatile ferroelectric random access memory (FERAM) applications.