The limitations on secondary ion micro-analytical performance imposed by ionization probabilities, mass spectrometer transmission, requirements for standards and sputtering artifacts have been investigated. The sensitivity of a modern magnetic mass spectrometer for sputtered B+ from oxidized Si is ~ 10-2 ions detected/atom sputtered. For this sensitivity, it is shown that ion microscopy of a part-per-million impurity is limited in lateral resolution to ~ 1 μm. For a 1% impurity, lateral resolution of ~ 30 nm is achievable. Depth profile analysis at the ppm level requires sample areas ~ 10 μm2. Isotope abundance determinations in volumes ~ 1 μm3 require the concentration of the least-abundant isotope to be > 1%.
"Limits of Quantitative Microanalysis Using Secondary Ion Mass Spectrometry,"
Scanning Electron Microscopy: Vol. 1985
, Article 7.
Available at: https://digitalcommons.usu.edu/electron/vol1985/iss2/7