Optimisation of RF magnetron sputtering and RTA-crystallisation of Pb(Zr0.52Ti0.48)O3 thin films by means of the orthogonal array method

Pb(ZrxTi1−x)O3 thin films are very attractive in microelectronics and microsystems applications for their enhanced ferroelectric and piezoelectric properties. However, deposition of this material requires multi-parameter complicated processes. This study validates the RF magnetron sputtering process and is based on an orthogonal array method allowing accurate research of the best sputtering parameters. The deposition is realized without substrate heating and without PbO excess in the target. PZT thin films are sputtered on Si/SiO2/Ti/Pt substrate with a satisfactory chemical composition, as given by Energy Dispersive Spectroscopy (EDS). A crack-free surface after Rapid Thermal Annealing (RTA) was obtained at a high sputtering pressure of 8 Pa. Pb stoichiometry is obtained for a high sputtering power (90 W corresponding to 3.8 W/cm2) and a large target–substrate distance (60 mm). An Ar/O2 (90:10) mixture of sputtering gas is used to avoid oxygen deficient films. X-Ray diffractometry (XRD) shows the perovskite phase with (111)-orientation, corresponding to the ferroelectric polarisation axis.