Surface-specific techniques XPS and SAM

Besides being surface specific. XPS and SAM possess the following advantages  

With the exception of H and He. all elements of the Periodic Table are detectable. including oxygen and carbon, and the elemental sensitivity is about 0.5 at %. 

In XPS, chemical-state information is easily obtained, since most elements can be identified as in metallic (e.g., Cu ) or oxidized form (e.g., Cu- ). Information may even be available as to the distinction between the chemical states of a given element with the same oxidation state but in different chemical environments (e.g., the O l.v binding energy (BE) has different values according to whether the O species is present in anhydrous oxides or in hydrates). 

The relative accuracies in quantitative determination are typically 5 in XPS and 20-30% in SAM, which are comparable to those obtained with bulk techniques. Quantitative determination is often combined with Ar+ 

SAM reveals the elemental lateral distribution with a spatial resolution that can be as good as 50 nm, which bridges the gap between SEM imaging (typically. 5 nm) and EPMA mapping (ca. 1 pm). 

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