Berlin 2005 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 7: Ionenstrahlverfahren I
DS 7.2: Vortrag
Samstag, 5. März 2005, 14:30–14:45, TU HS107
Formation of magnetic nanoclusters in crystalline silicon by ion implantation — •O. Picht1, W. Wesch1, E. Wendler1, N.A. Sobolev2, M.M. Araújo Oliveira2, and J. Heinrich3 — 1Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena — 2Departamento de Física, Universidade de Aveiro, Portugal — 3Innovent Jena
The research interest on magnetic semiconductors has been strongly increased over the last few years. While the focus mostly rested on the doping of II-VI and III-V compound semiconductors with transition metal ions such as Fe, Co, Ni and mainly Mn, there are only few publications on group IV semiconductors like Si and Ge. The formation of magnetic structures is mostly accomplished by chemical vapor deposition, molecular beam epitaxy or ion implantation. With the latter technique we consecutively implanted As and Mn ions at high fluences of 2·1016 at/cm2 into weak p-type Si (100). The implantation was carried out at a temperature of 350∘C and with energies of 200 keV (Mn) and 270 keV (As). After implantation, rapid thermal annealing (RTA) was carried out at 1100∘C for a time span of 30 s. Our Rutherford backscattering spectrometry (RBS) measurements indicate that a strong redistribution of both species takes place during the annealing processes. Whilst the As ions are partially incorporated into the Si-lattice and their movement seems to be governed mainly by diffusion, the Mn ions depth distribution shows additional peaks, resulting from nucleation at defect structures. The Ferromagnetic Resonance (FMR) and SQUID-measurements show ferromagnetic behaviour and suggest a Curie-Temperature over 300 K.