RF sputtered PLZT thin film on Pt/Ti electrode

PLZT (7.5/65/35) thin films were deposited by rf magnetron sputtering on single crystal Si substrates using an oxide sintered target with excess PbO. The effects of postannealing and bottom Pt/Ti electrodes on the thin film crystal structures and ferroelectric properties were studied. Film deposited at 200°C or below crystallizes to a perovskite phase after annealing treatment at 550° C or above, and the crystal structure depends on the annealing treatment. The best crystal structures and electronic properties were obtained when the thin films were annealed at 600° C to 650° C for l h in O2. For the Pt/Ti two-layer bottom electrode, the thickness of the Ti layer has a dominant effect. When the Ti layer was too thick or too thin, the PLZT thin film structures consist mainly of pyrochlore phases. However, using an appropriate Ti layer thickness, PLZT thin films having good crystal structures and ferroelectric properties can be obtained, with typical rémanent polarization value of 220 mC/m2 and coercive field strength of 6.5 MV/m.