Berlin 2005 – scientific programme

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DS: Dünne Schichten

DS 23: Postersitzung I

DS 23.39: Poster

Friday, March 4, 2005, 16:00–18:30, Poster TU B

Rare-earth scandate thin films as alternative gate oxides for microelectronic applications — •Tassilo Heeg¹, J. Schubert¹, M. Wagner¹, Y. Jia², L. Edge², D.G. Schlom², V.V. Afanas’ev³ und Ch. Buchal¹ — ¹Institut für Schichten und Grenzflächen ISG1-IT, Forschungszentrum Jülich GmbH, 52425 Jülich — ²Department of Materials Science and Engineering, Penn State University, University Park, PA 16802, USA — ³Semiconductor Physics Section, K.U. Leuven, Celestijnenlaan 200D, B-3001 Heverlee

The rare-earth scandates (ReScO₃, where Re is a rare earth element) were recently proposed as candidate materials for the replacement of SiO₂ in silicon MOSFETs in either amorphous or epitaxial form. In this work we investigate the dielectric properties and structural perfection of epitaxial and amorphous ReScO₃ thin films. Epitaxial LaScO₃, GdScO₃, and DyScO₃ films with good crystalline perfection were grown by pulsed laser deposition (PLD) on epitaxial SrRuO₃-films to form metal-insulator-metal structures on SrTiO₃(100) substrates. High K-values - up to 26 - were measured for these epitaxial scandate films. Amorphous films were prepared by PLD directly on silicon substrates. Internal photoeffect and photoconductivity measurements were performed to analyze the bandgap of the scandates and their band offset to silicon. The growth was also performed at different temperatures to investigate the thermal stability of the scandates in contact with silicon. The films were characterized using Rutherford Backscattering Spectrometry to investigate diffusion processes between silicon and the scandate thin films.