Stoichiometry and phase purity of Pb(Zr,Ti)O3 thin films deposited by metal organic chemical vapor deposition

(Pb,Zr)TiO3 (PZT) films have been prepared by metal organic chemical vapor deposition on 200 mm wafers. Phase pure perovskite films were deposited in a self-correcting region where the Pb stoichiometry is relatively insensitive to increasing Pb content in the gas phase. Films deposited with Pb flows lower than those used in the self-correcting region showed second phase ZrO2 whereas films deposited at Pb flows higher than those used in the self-correcting region showed second phase PbO. The PZT grains are columnar, extending from the bottom electrode to the top electrode. In the self-correcting region, PZT films of 70 nm nominal thickness show good ferroelectric behavior with switched polarization of similar to 40 mu C/cm(2) at 1.5 V and saturation voltage of similar to 1.2 V. The films have an average roughness of similar to 4 nm with grain size of similar to 700 A. The impact of the deposition parameters such as deposition temperature, pressure, precursor flow, and oxygen flow during deposition on the self-correcting region was investigated. Increasing the deposition temperature increases the width of the self-correcting region whereas increasing the oxygen flow narrows it. Pressure and the precursor flow do not impact the width although variation in pressure does shift the location of the self-correcting region. (c) 2006 American Institute of Physics.