Effect of LaNiO3 buffer layer thickness on the microstructure and electrical properties of (100)-oriented BaTiO3 thin films on Si substrate

BaTiO3 films were deposited on LaNiO3 buffered Si substrates with different LaNiO3 thickness. The LaNiO3 layer thickness dependence of the orientation, crystallinity, dielectric and leakage current properties for the BaTiO3 films was investigated. X-ray diffraction and scanning electron microscope results show that the increase of LaNiO3 thickness will improve the crystallization and grain size for the BaTiO3 films. Electrical measurements indicate that the BaTiO3 film grown on thicker LaNiO3 layer tends to exhibit higher dielectric constant, lower internal defect concentration and better insulating properties. The improved dielectric properties for BaTiO3 film on thicker LaNiO3 is suggested due to the combined result of improved electrical properties for LaNiO3 and improved microstructural properties for BaTiO3.