Mechanism of abnormal interface artifacts in SIMS depth profiling of a Si/Ge multilayer by oxygen ions

The abnormal interface artifact with two intense spikes was observed in secondary ion mass spectrometry depth profiling analysis of Si/Ge multilayer films by oxygen ion beam at the sputtering conditions where the Si surface is partially oxidized. The detailed step-by-step variations of the secondary ion intensities were investigated from the interface locations determined by the compositional depth profiles. Selective accumulation of the oxygen ions in the reactive Si layer and the implantation depth was suggested as the origin of the two-step interface artifact. The distances between the interfaces and the second spikes were well correlated with the implantation depth of the projected ions. Copyright (c) 2014 John Wiley & Sons, Ltd.