Mechanism of MCs⁺ formation in Cs based secondary ion mass spectrometry.

Quantitative analysis using MCs+ secondary ions has long been impossible because sample loading with Cs could not be controlled adequately. Using recently developed, advanced instrumentation, it can be shown that, at low levels of Cs loading, ionization and formation probabilities of MCs+ ions arrive at a constant, maximum level. On the basis of results obtained in three independent studies, involving three vastly different methods of controlling the sample loading with Cs, evidence is provided that MCs+ ions are emitted as such, independent of the number of atoms sputtered in the same impact event. Taken together, these findings finally pave the way for quantification of secondary ion signals without matrix effects