Berlin 2008 – scientific programme

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DS: Fachverband Dünne Schichten

DS 21: High-k Dielectric Materials - Synthesis, Properties, Applications

DS 21.5: Talk

Wednesday, February 27, 2008, 16:00–16:15, H 2032

Molecular beam deposition of LaLuO₃ thin films with high dielectric constant and low leakage current — •J. M. J. Lopes, U. Littmark, M. Roeckerath, St. Lenk, J. Schubert, and S. Mantl — Institute of Bio- and Nanosystems and Center of Nanoelectronic Systems for Information Technology, Research Centre Juelich, D-52425 Juelich, Germany

Although the introduction of hafnium-based high-κ dielectrics in the next CMOS generation has been announced, the implementation of materials with a dielectric constant even higher than 20 will be required in order to satisfy the future demands in CMOS applications. In this contribution, we report on lanthanum lutetium oxide, a ternary rare-earth based material that has recently appeared as a promising candidate¹. LaLuO₃ thin films were grown on (100) Si substrates by molecular beam deposition and electrically characterized by capacitance-voltage (C-V) and current-voltage (I-V) measurements. Additionally, a combination of characterization methods such as Rutherford backscattering spectrometry, transmission electron microscopy, X-ray reflectometry, and X-ray diffraction were used to study their composition and microstructural characteristics. We will present results of a systematic investigation on the film preparation, which allowed the deposition of LaLuO₃ thin films with EOT ≤1.5 nm, low leakage current densities of about 5 mA/cm² at -1 V gate bias, and higher κ-values around 30.
¹J. M. J. Lopes et al. Appl. Phys. Lett. 89, 222902 (2006).