Dresden 2014 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 24: Crystallography in Materials Science (Joint Session with KR)
DF 24.4: Vortrag
Donnerstag, 3. April 2014, 16:00–16:15, CHE 184
In-situ ion beam irradiation: X-ray scattering & diffraction experiments — Olga Roshchupkina, Carsten Baehtz, Stefan Facsko, Lothar Bischoff, Matthias Posselt, and •Joerg Grenzer — Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden
Ion beam techniques are widely used in semiconductor industry e.g. for introducing dopant atoms into materials. Ion implantation is characterized by fast dynamic processes associated with the evolution of collision cascades resulting in formation of defects such as vacancies, interstitials, etc. As a consequence, typically a strained layer that expands in the direction normal to the substrate surface is formed. This is due to the fact that the bulk material prevents any lateral macroscopic expansion and as a result the thin irradiated layer is subjected to an in-plane biaxial compressive stress. Ion irradiation is a very fast process and it is almost impossible to monitor it in-situ with the present x-ray sources. However, the accumulation of damage and the diffusion of defects are much slower processes and can be studied in-situ by X-rays. An in-situ ion beam implantation experiment was set up at ROBL/MRH at ESRF. Samples were irradiated using 20 keV He+ ions at room temperature. Reciprocal space maps to investigate the evolution of the strain depending on the accumulation of defects, as well as the conversion of the strained layer into a completely (X-ray) amorphous layer on single crystal Si and Al2O3 substrates were measured and discussed.