Influence of the morphology of ferroelectric SrBi 2 Ta 2 O 9 thin films deposited by metal organic decomposition on its electrical characteristics M. Moert a, * , G. Schindler a , T. Mikolajick a , N. Nagel a , W. Hartner a , C. Dehm a , H. Kohlstedt b , R. Waser b a Infineon Technologies AG, Koenigsbruecker Strasse 180, 01099 Dresden, Germany b Forschungszentrum Ju ¨lich, Institut fuer Festkoerperforschung (IFF), 52425 Juelich, Germany Received 5 September 2004; received in revised form 7 November 2004; accepted 7 November 2004 Available online 15 January 2005 Abstract The morphologies of SrBi 2 Ta 2 O 9 (SBT) thin films deposited by metal organic decomposition and crystallized at temperatures between 600 and 800 8C for 45 min are studied by atomic force microscopy (AFM) and X-ray diffractometry (XRD). From these analytical investigations a detailed quantitative description of the phase transformation from the non- ferroelectric fluorite to ferroelectric Aurivillius phase including changes in the microstructure and surface roughness are extracted. These results are correlated to electrical characteristics from hysteresis loop and leakage current measurements of corresponding Pt/SBT/Pt capacitor modules. As a result, increased values of remnant polarization can directly be correlated to the Aurivillius surface coverage. It is shown that the measured leakage currents are dominantly influenced by the grain boundaries and, therefore, are very sensitive on the overall film granularity. The SBT roughness is not predominant for the leakage currents, but is very critical for capacitor shorting. Potentially, the results provided with this work provide instruments for design of electrical characteristics, to meet desired FeRAM specifications. # 2004 Elsevier B.V. All rights reserved. PACS: 77.84.Dy; 81.10.Aj Keywords: Ferroelectric; SBT; Morphology; Hysteresis; Leakage current; Phase transformation 1. Introduction The ferroelectric material SrBi 2 Ta 2 O 9 (SBT) has been widely investigated for its applicability in non-volatile ferroelectric random access memory www.elsevier.com/locate/apsusc Applied Surface Science 249 (2005) 23–30 * Corresponding author. Tel.: +49 351 8866059; fax: +49 351 8867352. E-mail address: manfred.moert.drs@infineon.com (M. Moert). 0169-4332/$ – see front matter # 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.apsusc.2004.11.012