Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 12: Ionen-Festkörper-Wechselwirkung II

DS 12.6: Vortrag

Montag, 7. März 2005, 12:30–12:45, TU HS107

High-energy Au implantation of GaAs at 16 K — •E. Wendler, R. Lauck, and W. Wesch — Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena

In GaAs implanted with high-energy ions (10 MeV range) and analysed at room temperature, the defect concentration close to the surface was found to be lower than expected from theoretical simulations. Thermal or ionisation-induced annealing of defects was considered to be the cause for that. In the present paper GaAs was irradiated with 10 MeV or 17.5 MeV Au ions at 16 K and subsequently measured at the same temperature. Under these conditions ion-beam induced processes can be studied whilst thermal effects are widely excluded. It is found that the measured defect concentration scales with the number of displacements per lattice atom (representing the nuclear energy deposition) independent of the ion energy and of the depth. This result demonstrates that, for the chosen ion energies, the electronic energy deposition itself does not influence the damage production in GaAs. The explanation for the previously observed effects is a preferred annealing of lightly damaged areas during warming the samples to room temperature for measurement.