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DS: Fachverband Dünne Schichten

DS 10: Thin Film Characterisation: Structure Analysis and Composition (XRD, TEM, XPS, SIMS, RBS, ...) III

DS 10.6: Vortrag

Montag, 14. März 2011, 15:15–15:30, GER 38

Transmission of ballistic electrons through metal–insulator–metal heterosystems — Johannes Hopster¹, Marika Schleberger¹, Lars Breuer¹, Andreas Wucher¹, Alexander Bernhart¹, Mark Kaspers¹, Christian Bobisch¹, Rolf Möller¹, and •Detlef Diesing² — ¹Institut für Experimentalphysik, Universität Duisburg-Essen — ²Institut für Physikalische Chemie, Universität Duisburg-Essen

The transport of electrons through metal-insulator-metal heterosystems is determined by scattering processes in the metal layers and transport over or through the barrier in the insulator. We use an experimental setup combining a low energy electron gun with adjustable kinetic energy and a ballistic electron emission microscope (BEEM). Electrons with excess energies of up to 5 eV are injected by a STM tip in the silver top electrode of a tantalum/tantalum–oxide/silver tunnel junction. The ratio of detected electrons in the tantalum back electrode and electrons injected into the silver top electrode depends exponentially on the tip voltage and thus, on the excess energy of the electrons in a wide range from 1.7 to 4.2 V. In experiments with an electron gun the transmission with primary energies from 20 eV to 600 eV was studied. With energies up to 600 eV the yield shows a monotonous increase but the dependence on the energy turns from an exponential behavior to a linear behavior.