ESCA has two key advantages which make it important in yield, material, and failure analysis. The principle of ESCA utilizes a medium energy x-ray source (typically Mg Ka or Al Ka) to eject valence band electrons, or photoelectrons, from a sample. The process can also generates Auger electrons. Since the energy, or binding energy, of every valence band electron is different, very accurate spectro-analysis of these energy levels provides qualitative elemental and compound analysis. Because x-rays are used to excite the sample, charging is not a problem as it is for AES (Auger), EDX, or WDX. ESCA provides identification of chemical bonding.

Devitrifying glass was actively used for sealing CERDIP packages for many years. Many  manufacturers observed unexpected leakage between pins after post sealing processing steps. It has found that a metallic lead (Pb) was present on the surface of the frit between the pins. This information was separated from the peak for PbO. 

ESCA has been useful in understanding the chemical structure of the oxide-silicon interface. By removing the oxide by sputtering it is possible to measure the structure of the pre-oxidation cleaning compound which becomes bonded at the interface. This not only helps explain the differences between cleaning solutions, but also can aid in understanding  oxide instabilities/stabilities.