Growth of highly c-axis oriented SBN thin films on Si(100) with a MgO buffer layer by the sol-gel method

Dense and crack-free SBN thin films with the preferred c-axis orientation were successfully fabricated by the sol-gel method on Si(100) substrates with a MgO buffer layer. It was found that introducing the MgO buffer layer could effectively promote the formation of TTB SBN phase from SN and BN phases at lower temperature. Effects of annealing temperature and thickness of MgO buffer layer on the structural and morphological properties of SBN thin films were investigated. The SBN film with MgO buffer layer showed excellent epitaxy and densely packed grain morphology. The capacitance-voltage (C-V) properties of SBN films deposited on silicon substrates were found completely different from those of the films deposited on MgO-buffered silicon substrates, the C-V curves of SBN/Si films and SBN/MgO/Si films represent typical shapes of asymmetric and butterfly, respectively, indicating the improvement of the electrical properties and ferroelectric properties of the SBN films by introducing the MgO buffer layer.