Low-temperature metalorganic chemical vapor-deposition of perovskite PB(ZRXTI1-X)O3 thin-films
Pb (ZrxTi1-x)O3 thin films with perovskite structure were successfully prepared on sapphire disks, Pt/Ti/SiO2/Si, and RuOx/SiO2/Si substrates at temperatures as low as 550-degrees-C by hot-wall metalorganic chemical vapor deposition. Safe and stable precursors were used, namely: lead tetramethylheptadione [Pb(thd)2], zirconium tetramethylheptadione [Zr(thd)4], and titanium ethoxide. The deposition rates were in the range of 10.0 to 20.0 nm/min. The Auger electron spectroscopy (AES) depth profile showed good uniformity across the bulk of the films. The AES spectra also showed no carbon contamination in the bulk of the films. Zr/Ti ratio were easily controlled by the precursor temperatures and the flow rate of diluent gas. Optical constants were measured by a UV-VIS-NIR spectrophotometer. As-deposited films were dense and showed uniform and fine grain size. The 600-degrees-C annealed film (Pb/Zr/Ti=50/41/9) showed a spontaneous polarization of 23.3-mu-C/cm3 and a coercive field of 64.5 kV/cm.