Electrical properties of ferroelectric BaTiO3 thin film on SrTiO3 buffered GaAs by laser molecular beam epitaxy

Ferroelectric BaTiO3 thin films were epitaxially grown on (001) GaAs substrate using SrTiO3 as a buffer layer by laser molecular beam epitaxy. The perovskite SrTiO3 buffer layer present a body centered cubic structure by formation of an interfacial layer with the [100]SrTiO3∥[110]GaAs in-plane relationship. Thereupon, a highly c-oriented BaTiO3 thin film was grown on SrTiO3/GaAs in a layer by layer mode. Enhanced electrical properties of the heteroepitaxial structure were demonstrated. The BaTiO3(150 nm)/SrTiO3/GaAs system demonstrates hysteresis loops with a remnant polarization of 2.5 μC/cm2 at 600 kV/cm and a small leakage current density of 2.9×10−7 A/cm2 at 200 kV/cm.