Preparation of Zr-rich Pb(Zr,Ti)O3 films by sol-gel technique

Zr-rich lead zirconate titanate [Pb(ZrxTi1-x)O-3 (PZT)] (x =0.9) films were fabricated by sol-gel technique, using lead (II) acetate trihydrate, zirconium (IV) propoxide, and titanium tetraisopropoxide as source materials. Final heat treatment of rapid thermal annealing was done at 735degreesC for 4 min. PZT films fabricated directly on Ir/SiO2/Si substrate had a large grain size of 10-20 mum and bad electric properties, derived by the lack of adhesion. To arrange the adhesion of Ir surface, thin Ti film (similar to1 nm) was introduced to Ir surface as a buffer layer. Employing the Ti layer, PZT grain size decreased to less than 1 mum. From the temperature dependence of dielectric constant, Curie temperature was 260degreesC and dielectric constant at 26degreesC was 750. Symmetric D-E hysteresis loop was observed, and remanent polarization and coercive field were 20 muC/cm(2) and 65 kV/cm, respectively. Zr-rich PZT film derived from sol-gel technique is expected to apply to ferroelectric memory and pyroelectric devices.