GOOD FERROELECTRICITY OF Pb(Zr,Ti)O3 THIN FILMS FABRICATED BY HIGHLY REPRODUCIBLE DEPOSITION ON BOTTOM Ir ELECTRODE AT 395 C

Polycrystalline Pb(Zr,Ti)O3 (PZT) films were prepared on (111)Ir/TiO2 /SiO2/Si and (111)Pt/TiO2/SiO2/Si substrates at 395 C by source-gas-pulsed-introduced MOCVD (pulsed-MOCVD). By decreasing the deposition pressure from 670 to 67 Pa, a highly reproducible process was obtained irrespective of the type of substrate, used by accelerationing of the reevaporation of excess Pb from the surface of the film. It was found by XRD reciprocal space mapping measurement that a reaction product of Pb and Pt, PbPtx, is formed at a deposition pressure of 67 Pa for the films deposited on the (111)Pt/TiO2/SiO2/Si substrate. However, this reaction product was not detected for those deposited on the (111)Ir/TiO2/SiO2/Si substrate. PZT films with ferroelectricity and a remanent polarization value of 40 mu C/cm2 were fabricated on the (111)Ir /TiO2/SiO2/Si substrates with high reproducibility even at 395 C. This shows that Ir is a candidate bottom electrode for the highly reproducible preparation of MOCVD-PZT films having a good interface with the bottom electrode, good ferroelectricity and a remanent polarization value of 40 mu C/cm2. 20 refs.