Fabrication and characterization of ferroelectric Pb(ZrxTi1-x)O-3 thin films by metalorganic chemical vapor deposition

Ferroelectric Pb(Zr, Ti)O-3 (PZT) thin films were grown on Pt/Ti/SiO2/Si, R uO2/Pt/Ti/SiO2/Si, and Pt/MgO substrates at the substrate temperature of 60 0 degrees C by the metalorganic chemical vapor deposition (MOCVD) method. P b(C11H19O2)(2)(Pb(DPM)(2)), Ti((OC3H7)-C-i)(4), and Zr(O'C4H9)(4) as source material and Ar and O-2 as a carrier gas and oxidizing agent were selected , respectively. In order to investigate the effect of Zr and Ti component c hanges on the growth aspect of PZT thin films, Zr and Ti source materials w ere varied by controlling Zr and Ti flow rate. From the Rutherford backscat tering spectroscopy (RBS) measurement, it was confirmed that the compositio n of the films, particularly Pb content, changed with the increasing Zr flo w rate. In addition, the x-ray diffraction (XRD) spectra analysis showed th e existence of a Pb-deficient pyrochlore phase as well as ZrO2 as a seconda ry phase. From these results, it is believed that the higher Zr partial pre ssure in the gas phase reduces the sticking of the Pb precursor to the subs trate. The film with Pb:Zr:Ti = 1:0.42:0.58 showed a dielectric constant of 816 at 1 MHz. The spontaneous polarization, remanent polarization, and coe rcive field measured from the RT66A by applying 3.5 V were 44.1 mu C/cm(2), 24.4 mu C/cm(2), and 59.6 kV/cm, respectively. The fatigue analysis of PZT thin films with Pb,Zr:Ti = 1:0.42:0.58 at an applied voltage of Vp-p = 5.4 V showed 40% degradation on the basis of initial polarization value after 10(9) cycles.