Influence of the gas mixture ratio on the electrical and ferroelectric properties of PLZT thin films

A (Pb0.92La0.08)(Zr0.65Ti0.35)O-3 (PLZT) ferroelectric thin film was deposited on deposited on TiO2 buffered layer on top of a Pt/Ti/SiO2/Si substrate by RF magnetron sputtering method. The effect of the Ar/O-2 partial pressure ratio on the ferroelectric properties of PLZT thin films was investigated at various Ar/O-2 partial pressure ratios such as 27/1.5, 23/5.5, 21/7.5 and 19/9.5 sccm. The crystallinities of PLZT thin films were analyzed by XRD. The surface morphology was characterized by FESEM. The P-E hysteresis loops, the remnant polarization characteristics and the leakage current characteristics were obtained using a precision LC. With an increase of the oxygen partial pressure ratio, the crystallinity was decreased. Also the preferred orientation of PLZT thin films was changed from the (110) plane to the (111) plane. Results indicated that the change of the oxygen partial pressure ratio significantly affects the thin film surface morphology and the ferroelectric properties.