Berlin 2008 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 13: Dielectric and ferroelectric thin films and nanostructures III
DF 13.2: Vortrag
Donnerstag, 28. Februar 2008, 14:20–14:40, EB 107
Characterisation of thin tantalum oxide films — •Katrin Bruder1, Achim Walter Hassel1, and Detlef Diesing2 — 1Max-Planck-Institut für Eisenforschung, Max-Planck-Str. 1, 40237 Düsseldorf — 2Institut für physikalische Chemie, Universität Duisburg-Essen, 45141 Essen
Metal-Insulator-Metal (MIM, consisting of tantalum– anodic tantalum oxide–platinum) contacts were investigated by means of IV characteristics and impedance spectroscopy. With impedance spectroscopy it is possible to determine the capacitance, the metals resistivities and the tunnel resistance. The latter one is a function of the bias voltage, while the capacitance and metals resistivities remain constant. The tunnel resistivity was found to have a maximum at a bias Umax slightly different from 0 V. This shift was investigated as a function of the film thickness (d=4 nm to 12 nm) and the temperature in the range from T = 58 K to 350 K. The measurements were compared to simulations. These simulations show, that for an explanation of this shift, asymmetrical barriers and tunneling through the valence band has to be considered.