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Organometallic chemical vapor-phase deposition (MOCVD) of oxidic high-#epsilon# layers / Metallorganisch chemische Gasphasenabscheidung (MOCVD) von oxidischen hoch-#epsilon# Schichten

Authors
  • Regnery, S.
  • technische, rheinisch-westfaelische
  • juelich, forschungszentrum
Publication Date
Jan 01, 2005
Source
OpenGrey Repository
Keywords
Language
German
License
Unknown

Abstract

The considered materials in this work are (Ba,Sr)TiO_3, SrTiO_3 and SrTa_2O_6 and the oxides from the group IVb metals: Ti, Zr and Hf. The films were deposited on Platinum and Silicon substrates in order to evaluate the dielectric properties for applications in metal-insulator-metal (MIM) structures as well as in metal-insulator-semiconductor (MIS) structures. The high-k films were grown by metal organic chemical vapour deposition (MOCVD) and the evaluation and optimisation of the production processes is a major part of this work. Different approaches were investigated: mixing of conventional precursors for the example of (Ba,Sr)TiO_3, test of a single source precursor for SrTa_2O_6 and tests of newly designed precursors for the group IVb-metal oxides, M-(O-I-Pr)_2(tbaoac)_2. In addition, compatibility tests of the new Titanium precursors with the conventional Strontium precursor are presented for the example of SrTiO_3. Most detailed investigations were performed on the nucleation and growth processes of (Ba,Sr)TiO_3 on platinum <111>. Details of the nucleation were obtained from the new method of conductivity scans with the AFM. These investigations were combined with XRD, SEM, HRTEM, SPM and XPS and give a consistent picture of development of the structural properties and their dependencies on growth temperature and chemical composition. The electrical properties, especially capacity and leakage current indicate a strong dependency from film thickness, which can be explained by separating the bulk- from the interface capacity. Based on these results the interface layer was optimised by changing the interfacial stoichiometry. Additionally, SrTa_2O_6 was tested as an alternative material with low tunability and shows promising electrical results. For the example of SrTiO_3 on silicon <001> details of the growth kinetics of the interfacial layer were investigated by HRTEM. The first results from group IVb oxides, which are the most promising candidates for gate oxides, are presented. (orig.) / Available from TIB Hannover: RA 931(4159) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische Informationsbibliothek / SIGLE / DE / Germany

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