Thickness and temperature dependent electrical characteristics of SrBi2Ta2O2 thin films prepared by pulsed laser ablation

Polycrystalline SrBi₂Ta₂O₉ (SBT) thin films have been prepared by pulsed laser ablation technique on platinum coated silicon substrate. The influence of growth temperature and thickness on microstructure and dielectric properties of films was studied. Crystallite size of SBT films has been found to increase with increasing substrate temperature. With increase of substrate temperature from 500 to 700°C, the dielectric constant gradually increases due to increase in the cystallinity and gain size. Thickness dependent dielectric constant has been studied and discussed in the light of an interfacial dead layer and the finite screening length of the electrode. The C-V measurement of the film deposited at 700°C exhibited butterfly-like curve, which is characteristics of ferroelectric nature of material. The frequency dependent dielectric constant and the dielectric loss of SBT films for various processing temperature was also studied.