Performance and limitations of electron probe microanalysis applied to the characterization of coatings and layered structures

Abstract

Electron probe microanalysis (EPMA) at low electron energies (typically 3–10 keV) has been used to study the composition of coatings with a film thickness of 0.1–1.3 μm (“bulk” analysis). The accuracy of quantification, including the most critical situation of low atomic number elements (boron–oxygen), is about 5% relative by use of pure element or arbitrary compound standards. A special procedure of data processing (“thin film” analysis) enables the simultaneous determination of film thickness and composition, provided that the substrate is known. The film thickness may be in the range of 2 nm to 5 μm. EPMA can be also applied in the mode of “non-destructive in-depth analysis”, which is based on the combined evaluation of experiments at different electron energies. The quantitative characterization of layered structures and implantation zones is demonstrated.