State-of-the-art SIMS instruments allow to produce 3D chemical mappings with excellent lateral (50 nm on
Cameca’s NanoSIMS 50) and depth (1nm range) resolutions. Considerable efforts are currently spent to
further improve the spatial resolution of SIMS instruments. On the one hand, the development of new ion
sources with an increased brightness allows producing smaller spot sizes and thus increased lateral
resolutions. On the other hand, new ion optics permitting lower impact energies of the primary ions reduce
the dimensions of the collision cascades in the sample and hereby improve the depth resolution.
The obtained 3D resolution is however often much worse than what could be expected considering the
instrumental performances. As a matter of fact, the sample surface presents an initial roughness which leads
to an uncertainty on the depth scale. Moreover, this roughness changes during the ion bombardment as the
local sputtering yields depend on parameters such as the local angle of incidence of the ion beam, the crystal
orientation. Complementary in-situ Atomic Force Microscopy (AFM) mappings of the surface roughness of the sample
would allow correcting the SIMS images with respect to the artefacts mentioned above. A careful image
overlay procedure would ensure exact alignment of the resulting AFM images with the area analyzed by
SIMS. As a consequence, the total eroded depth could be determined as a function of the lateral position
within the sputter crater, thus allowing an independent depth scale calibration on each pixel of the imaged
area. Combining the mass spectral data processed this way with the topography information from the AFM
images, it would be possible to reconstruct the true spatial distribution of species within the investigated
sample volume.

This project thus aims at combining SIMS with Scanning Probe Microscopy (SPM). A first step will consist
in defining the specifications of the combined SIMS-SPM instrument. In this context, a dedicated study will
allow to evaluate the advantages and limitations of the combined SIMS-SPM technique, to elaborate analysis
protocols, to improve the different instrumental developments.

Based on the technological developments and the experimental results obtained during stage 1, the SPM will
be integrated in a second step into the Cameca NanoSIMS instrument. This system integration will be
completed with dedicated data treatment software allowing easy and quick routine analysis protocols.
Finally, the performances and analytical potential of the combined SIMS/SPM system will be demonstrated
on a multitude of samples chosen from the different fields of application mentioned previously.
A commercialisation strategy for the integrated SIMS-SPM system (either as an add-on accessory for
existing SIMS instruments or as a complete instrument in collaboration with a SIMS manufacturer) will be
set-up during this project by the partners.