High Resolution Surface Analysis by TOF-SIMS

Abstract

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has developed into a mature technique meanwhile applied in many industrial laboratories for elemental and molecular surface characterization. Not only spectroscopic information but also information on the lateral distribution of surface species can be obtained (TOF-SIMS Imaging). The lateral resolution for the detection of elements is well beyond 100 nm using modern liquid metal ion guns. For molecular species, however, the achievable lateral resolution not only depends on the performance of the instruments but also on sample parameters like obtainable secondary ion yield and the area disturbed on the sample by impact of a single primary ion. Whereas for larger molecules the achievable resolution can be several micron, imaging with sub-μm resolution is possible if one monitors characteristic fragment ions.