Properties of SBT films crystallized by pulsed excimer (KrF) laser annealing

Structure and ferroelectric properties of SrBi2Ta2O9 (SBT) films crystallized by pulsed laser annealing of amorphous SBT films have been investigated. The amorphous SBT thin films of 500 nm in thickness were prepared by pulsed laser deposition (PLD) on Pt/TiO2/SiO2/Si at a substrate temperature of 400 °C. It is revealed that bi-layered SBT film composed of a well-crystallized peroveskite ferroelectric SBT upper layer of 250 nm thick and an amorphous non-ferroelectric SBT layer with the same thickness lying under the crystallized layer can be formed after the films were irradiated for 40 s with a 248 nm excimer laser beam at a energy fluence of 120–140 mJ cm−2, a pulse width of 30 ns and a frequency of 20 Hz. Ferroelectric hysteresis loop of the bi-layered SBT films have been measured, from which a remnant polarization of 1.5 μC cm−2 and a coercive field of 17 kV cm−1 of the laser crystallized SBT layer have been evaluated.