Optimization of the Collection Efficiency of Secondary Ions for Spatially Resolved Secondary Ion Mass Spectrometry in Crossbeam Devices

摘要

With the presented method a high collection efficiency is achievable even for a soft primary ion bombardment of 100 pA. Secondary ion currents from 0.1 pA up to 100 pA, which correspond to a number of roughly 103 up to 106 ions per millisecond! The optimized collection of the secondary ions makes it possible to perform a high speed mass analysis. Both positive and negative ions can be collected by changing the polarity of the SIMS tip and correspondingly adjusting the tips potentials of Gemini and FIB.