Grain morphology and cation composition heterogeneity of Pb(Zr_xTi_1-x)O₃ thin films deposited by metal-organic chemical vapor deposition
I-F. Tsu*, G-R. Bai*, C.M. Foster*, K.L. Merkle*, K.C. Liu+
(*Argonne National Laboratory, +University of Wisconsin-Madison)
The preferred orientation, grain morphology and composition heterogeneity of the polycrystalline Pb(Zr_xTi_1-x)O₃ (PZT) thin films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and x-ray energy dispersive spectroscopy (EDS). PZT thin films with nominal x = 0.5 were grown by metal-organic chemical vapor deposition (MOCVD) on (110)- and (101)-textured RuO₂ bottom electrodes at temperatures ² 525¡C. Columnar grain microstructure with strongly faceted surface morphology was observed in both films. The grain morphology and surface roughness of the PZT films were observed to depend on those of the underlying RuO₂ layers. TEM-EDS analysis shows notable cation composition heterogeneity in length scales of 0.2Ð2 <>mm. Pronounced Pb composition deficiency and heterogeneity were also observed in PZT/(110)RuO₂ in length scales above 40 <>mm. The grain morphology and cation heterogeneity of the PZT films are discussed on the basis of diffusion-limited columnar growth mechanism.
Keywords: ceramics; microstructure; chemical vapor deposition (CVD)
Order No.: JA806-024 © 1998 MRS

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