DSIMS elemental sensitivity

Dynamic secondary ion mass qrectrometry (DSIMS) and Rutherford back scattering (RBS) are techniques that can provide information about composition profiles in polymer films. Both techniques provide elemental sensitivity, but neither will provide chemical bonding information as NEXAFS does, since both techniques rely on mass differences as a contrast mechanism. The depth profile is obtained on the basis of elemental conq>osition profiles in the film. In... 

The relatively intense mono-energetic beams of primary ions (energy range of 0.5-50 keV) used in dynamic SIMS erode the sample surface at sputtering rates ranging between 0.1 and 10 nm/sec (depth probed 2 nm-100 fim) and produce predominantly elemental ions or low-mass cluster ions. DSIMS allows mapping of elemental and molecular distributions (mapping) in all three dimensions and achieves ppm to ppb detection sensitivities for... 

Dynamic SIMS (DSIMS) operates under conditions designed to remove surface layers sequentially during the analysis. This is achieved by rastering a primary ion beam over the area of analytical interest and collecting the emitted secondary elemental or cluster ions in the MS system. The erosion rates can be controlled from a few nanometres per hour to several tens of micrometres. The technique provides high sensitivity, quantitative elemental information in the form of mass spectra, depth profiles, and two- and three-dimensional images. All elements in the periodic table can be detected with sensitivities in the parts per million to parts per billion range. 

SIMS is based on the emission of atomic and molecular particles (.secondary ions) from the surface of a solid under bombardment with primary particles (ions). Under DSIMS conditions, the erosion rate is of the order of mono-layers) per second and concentration depth profiling can be performed with high spectrometric sensitivity, in favorable cases down to the ppb level. The. sensitivity of SIMS is element dependent and varies from I ppb to 100 ppm. and the technique is therefore used for trace and ultratrace analysis. 

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