Olivier Scholder oral presentation (PB1-Mon3-1-2)
The route towards nm-scale resolution with a combination of ToF-SIMS and Scanning Probe Microscopy
EMPA, Überlandstrasse 129, 8600 Dübendorf, Switzerland
Improving the imaging lateral resolution is a topic of growing importance to fulfill the needs of the miniaturization trend of novel devices and functional materials. The often sophisticated processes involved in the fabrication of those small objects also lead to an increased amount of morphological and chemical defects, which makes the ability to resolve their chemical composition at high lateral resolution crucial. Tof-SIMS provides outstanding chemical contrast with limited lateral resolution (~100 nm) while Scanning Probe Microscopy (SPM) oﬀers sub-nanometer scale resolution, but with limited material contrast. Here, we present a combination of these two techniques in order to achieve chemical imaging with nanometer-scale lateral resolution and without having to trade off the intensity, such as with the well-known "ToF-SIMS extreme beam cross-over" operational mode for example.
In ToF-SIMS imaging, several factors influence the lateral resolution of the image data, such as thermal and charging drifts, emission current instabilities and matrix-effect, to name a few. Based on the co-imaging of a reference sample with SPM and ToF-SIMS, we show how the ToF-SIMS point spread function including all these effects can be extracted. Then, via a deconvolution algorithm, we reconstruct the ToF-SIMS data with significantly enhanced lateral resolution. The efficiency of the presented algorithm is assessed in terms of the inﬂuence of the different parameters involved.