Impact of Pt bottom electrode on the properties of ferroelectric Bi3.25La0.75Ti3O12 capacitors

Lanthanum-modified bismuth titanate (Bi3.25La0.75Ti3O12) (BLT) films have been prepared on platinized silicon substrates using sol–gel method. Highly (001) or (111) oriented platinum layers are used as the bottom electrodes of ferroelectric BLT capacitors to study the effects of Pt orientation on the structural and physical properties of BLT films. X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements demonstrate that the microstructure and morphology of BLT films are not strongly affected by the Pt films. BLT film on highly (111) oriented Pt possesses much higher remanent polarization (∼ 8 μC/cm2) than that on highly (001) oriented Pt although the coercive fields of the two kinds of Bi3.25La0.75Ti3O12 films are almost equal.