Improvement of Ferroelectrics Properties of Lead-Free Thin Films by Sol Gel Process Optimization

This work deals with the optimization of lead-free piezoelectric/ferroelectrics oxides thin films fabrication process. Such films, with formula 0.5(BaZr0.2Ti0.8O3)-0.5(Ba0.7Ca0.3O3) (BZT-BCT), were deposited on Pt/TiOx/SiO2/Si wafers. The thin films fabrication process by sol-gel process consists of repeated chemical solution deposition routes, whose spin coating and heating parameters were optimized to reduce the residual stresses that are the major cause of cracking in the films. The results indicated that 250 nm thick films were obtained with limited presence of cracks and improved ferroelectric properties because of the enhanced morphological properties of the deposited layers.