An ESCA spectrum consists of a series of peaks corresponding the the binding energies of the photoelectrons that produced these peaks.

The above ESCA survey scan of a failed solder joint shows multiple peaks of Pb, Bi, Ag, Sn, Cl, C, and O. By measuring the area under the peaks of these elements and multiplying by sensitivity factors, quantitative analysis can be performed.

ESCA analysis not only provides elemental information, but because the technique is detecting the binding energy of emitted electrons, it can also provide some chemical bonding information. Depending on what elements the parent atom is bound to, the binding energy of the emitted photoelectrons may shift slightly. The instrument is sensitive enough to detect these electron energy shifts and use them to determine what chemical compounds are present.

The following two ESCA spectra of titanium surfaces are used for an example:

The above spectrum is a detail scan of a titanium surface. To produce such a scan, the detector sweeps just the energy range of the desired peak at a higher resolution. The largest ESCA peaks for titanium are produced by the 2p orbital electrons. The spectrum shows two distinct 2p peaks, due to the difference in the 2p1 and 2p3 spin on the electrons in this orbital. Since there are only two peaks visible (one from each of the 2p1 and 2p3), there is only one chemical species detected. The binding energy of the 2p3 electron was 453.55 eV, which means this titanium surface is composed of metallic titanium

The above titanium detail scan is deconvoluted into six distinct peaks. Since the titanium 2p orbital produces two peaks, this means there are three different chemical species present. The 2p3 binding energy values of these peaks are 453.60 eV, 455.22 eV, and 457.63 eV. These binding energy values correspond to elemental titanium (metallic), titanium carbide, and titanium oxide (TiO2).

The ECSA spectrometer is also equipped with an argon ion gun which allows depth profiling of the sample surface. This is extremly usefull in determining if contaminants are only present on the surface or reside in the sample bulk

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