Bi2O3 buffer layers were deposited on Pt/Ti/SiO2/Si substrates by an R.F. magnetron sputtering method in order to improve the ferroelectric properties of SBT (SrBi2Ta2O9) thin films. The volatility of bismuth brings about an obvious non-stoichiometry of the SBT thin films and causes secondary phases to appear. The Bi2O3 buffer layers were found effective in achieving a lower crystallization temperature and in interrupting the diffusion of Pt towards SBT thin films. In this experiment, we have found that the presence of Bi2O3 buffer layers was responsible for the enhanced ferroelectric properties and crytallinities of SBT thin films.
Keywords: Ferroelectric film, SrBi2Ta2O9 (SBT), Bi2O3 buffer layer, Substrate temperature.