Quantification Depth scale

Quantification in shallow profiles is another issue for quantitative analysis with SIMS. Matrix effects and sputtering rate changes are necessary considerations in quantification of shallow profiles to obtain an accurate profile with concentration and depth scales [14]. Comparison to high resolution Rutherford backscattering (HRBS) data helps in evaluating shallow SIMS profiles [36]. 

Secondary ion emissions are collected as a function of sputter time, or more precisely, the primary ion dose. This is a result of the fact that each primary ion impact has a statistical likelihood of removing atoms and/or molecules from the surface of the substrate of interest. If more than one atomic layer is removed per analytical cycle, as is carried out in Dynamic SIMS, quantification of the depth scale may be required. For obvious reasons, this requirement does not extend to the Static SIMS regime. 

Quantification is in many cases the most important feature of XPS [52]. The X-ray photoelectron current produced by an incident X-ray photon of energy hv, which ionises core level Z in an atom of type A in a solid matrix (M), is a function of both energy- and matrix-dependent terms. Quantification of XPS spectra is thus far from simple. In fact, already the exact definition of quantification is complicated. Even for an ideal sample the actual escape depth may vary substantially. The depth of photoelectron detection, for a given XPS system, may vary dramatically from measurement to measurement, and even within the same measurement (in relation to the energy scale). After some experimental... 

Conversion of the sputter time scale to either the depth (as applies to Dynamic SIMS) or the surface coverage removed (as applies to Static SIMS) can be a relatively straightforward procedure. This is outlined in Section 5.4.2. Owing to the intricate interplay of intrinsic matrix effects with analysis-induced matrix effects, conversion of the intensity scale can be much more difficult. Indeed, effective quantification of the concentration scale requires the complete removal of all matrix... 

---