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A combination of dynamic secondary ion mass spectroscopy (DSIMS) and time-of-flight low-energy ion scattering (TOF-LEIS) has been applied to acquire a composition depth profile of MoSi multilayers. During the sequential Ar+ sputtering secondary ions were monitored while in-between the sputtering cycles the TOF-LEIS spectra of scattered He neutrals were acquired. All the measured TOF-LEIS spectra versus sputtering time were displayed in one bitmap from which the depth profiles for different scattering depths were derived and analyzed. Analyzing the TOF-LEIS spectra of He particles scattered from the areas below the layer altered by ion-beam mixing led to an improvement of the depth resolution. In this way the resolution limits due to mixing phenomena can be overcome. Finally, the direct comparison of the DSIMS and TOF-LEIS depth profiles was carried out.

A classical dynamics simulation of the low energy He+ ion scattering on a Cu(100) surface was carried out for a more detailed explanation of LEIS azimuthal scans with respect to a previous work. The Thomas-Fermi–Moliere screened potential was used in the calculations to describe interatomic repulsive interactions. A stopping power and thermal vibrations of target atoms were involved as well. The results of the simulations were compared with the experiment and thus the correction factors of interatomic scans found. The main features of the calculated azimuthal scans N(Φ) are discussed and the relevant parts compared. Additionally, ion blocking effects were studied by the analysis of N Φ , β distribution of ions backscattered into the whole half-space above the Cu(100) surface. This gave us a more transparent view into the low energy ion scattering processes on this periodic surface.

In this paper focused ion beam milling of very shallow nanostructures in silicon and germanium by low energy Ga + ions is studied with respect to ion beam and scanning parameters. It has been found that, using low energy ions, many scanning artefacts can be avoided and, additionally, some physical effects (e.g. redeposition and ion channelling) are significantly suppressed. The structures milled with low energy ions suffer less subsurface ion beam damage (amorphization, formation of voids) and are thus more suitable for selected applications in nanotechnology. (Some figures in this article are in colour only in the electronic version)