The most sensitive elemental & isotopic surface microanalysis technique
Introduction to the SIMS technique
When a solid sample is sputtered by primary ions of few keV energy, a fraction of the particles emitted from the target is ionized. Secondary Ion Mass Spectrometry consists of analyzing these secondary ions with a mass spectrometer. Secondary ion emission by a solid surface under ion bombardment supplies information about the elemental, isotopic and molecular composition of its uppermost atomic layers. The secondary ion yields will vary greatly according to the chemical environment and the sputtering conditions (ion, energy, angle). This can add complexity to the quantitative aspect of the technique. SIMS is nevertheless recognized as the most sensitive elemental and isotopic surface analysis technique.
The SIMS technique provides a unique combination of extremely high sensitivity for all elements from Hydrogen to Uranium and above (detection limit down to ppb level for many elements), high lateral resolution imaging (down to 40 nm), and a very low background that allows high dynamic range (more than 5 decades). This technique is "destructive" by its nature (sputtering of material). It can be applied to any type of material (insulators, semiconductors, metals) that can stay under vacuum.
While Static SIMS concentrates on the first top monolayer, providing mostly molecular characterization, in dynamic SIMS mode, bulk composition and depth distribution of trace elements are investigated with a depth resolution ranging from sub-nm to tens of nm. This is why SIMS is one of the most widespread surface analysis techniques for advanced material research.
CAMECA: world leader in SIMS
Since pionneering Secondary Ion Mass Spectrometry in the 1960's, CAMECA has developed a complete SIMS product line. Each of our high-end instruments ensures the best performance for a given application.
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