Surface morphologies of Ge and Si under heavy single-atom and poly-atom ion irradiation


Surface morphologies of Ge and Si under heavy single-atom and poly-atom ion irradiation

Bischoff, L.; Böttger, R.; Heinig, K.-H.

Well-ordered dot patterns can be obtained at normal irradiation on Ge and Si with polyatomic Bi ions of ~10…20 keV kinetic energy per atom. Similar patterns were found with monoatomic Bi ions at elevated Ge substrate temperatures, when the energy per Ge atom exceeds a critical value.
To identify the driving force for this unexpected dot pattern formation, focused ion beam and broad beam studies have been performed in parallel with molecular dynamics and kinetic Monte-Carlo simulations. This investigation proves that these patterns appear only, if nanomelt pools form at the surface of irradiated Ge or Si. It will be shown that melt pools induce a surface smoothing process like in the well-known laser polishing technology. Contrary, surface destabilization results from the shift of the center of the melt pool meniscus with respect to the ion impact point, where the meniscus arises from the missing material due to sputtering.

Keywords: polyatomic Bi ions; germanium; silicon; melt pool

Related publications

  • Lecture (Conference)
    Workshop „Ionenstrahlen in Forschung und Anwendung“ & Treffen der DFG-Forschergruppe FOR 845, 12.-14.06.2013, Leipzig, Germany

Permalink: https://www.hzdr.de/publications/Publ-18880
Publ.-Id: 18880