GRAIN MORPHOLOGY AND CATION COMPOSITION HETEROGENEITY OF PB(ZRXTI1-X)O-3 THIN-FILMS DEPOSITED BY METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION

The preferred orientation, grain morphology, and composition heterogen eity of the polycrystalline Pb(ZrxTi1-x)O-3 (PZT) thin films were char acterized by x-ray diffraction (XRD), scanning electron microscopy (SE M), atomic force microscopy (AFM), transmission electron microscopy (T EM), and x-ray energy dispersive spectroscopy (EDS). PZT thin films wi th nominal x = 0.5 were grown by metal-organic chemical vapor depositi on (MOCVD) on (110)- and (101)-textured RuO2 bottom electrodes at temp eratures less than or equal to 525 degrees C. Columnar grain microstru cture with strongly faceted surface morphology was observed in both fi lms. The grain morphology and surface roughness of the PZT films were observed to depend on those of the underlying RuO2 layers. TEM-EDS ana lysis shows notable cation composition heterogeneity in length scales of 0.2-2 mu m. Pronounced Pb composition deficiency and heterogeneity were also observed in PZT/(110)RuO2 in length scales above 40 mu m. Th e grain morphology and cation heterogeneity of the PZT films are discu ssed on the basis of diffusion-limited columnar growth mechanism.