Engineered core-shell Si1−xGex/Ge nanowires fabricated by focused ion beam and oxido-reduction

Mansour Aouassa (1) , A. Ronda (1) , Luc Favre (1) , A. Delobbe (2) , P. Sudraud (2) , Isabelle Berbezier (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 ZAC Saint Charles - Orsay Physics

We demonstrate that perfectly reproducible and homogeneous core-shell Si1−xGex/Ge nanowires can be produced by a two step nanofabrication process. The process makes use of a combination of Liquid Metal Alloy Ion Source–Focused Ion Beam (LMAIS-FIB) nanomilling and condensation. In a first step, we fabricate arrays of SiGe wires by LMAIS-FIB milling of fully relaxed Si1−xGex pseudo-substrates. The use of Ge2+ ions during this step avoids any metallic contamination of the nanowires. In a second step, we both reduce the diameter of the wires and form the core-shell configuration by oxido-reduction of the wires. Large arrays of core-shell nanowires with extended aspect ratio (length over diameter), small diameters and ultra-thin shell thickness are fabricated. Multilayer core-shell configurations with tunable arrangements could also be produced by repeated condensation cycles.

Domaines: Matière Condensée [cond-mat]

Mansour Aouassa, A. Ronda, Luc Favre, A. Delobbe, P. Sudraud, et al.. Engineered core-shell Si1−xGex/Ge nanowires fabricated by focused ion beam and oxido-reduction. Journal of Applied Physics, 2013, 114 (3), pp.034301--034301--5. ⟨10.1063/1.4813097⟩. ⟨hal-01811411⟩