Auger Electron Spectroscopy (AES)

Auger electron spectroscopy (AES) is a surface-sensitive analytical technique with high lateral resolution. It is used to quantify and map the elemental composition of the outermost 2-10 nm of a material.

Strengths

• Very high lateral resolution (as small as 5 nm)
• Provides quantitative elemental composition and chemical state identification
• Acute surface selectivity (typical information depth is ~ 3 to 10 nm)
• Excellent for elemental mapping

Limitations

• Reproducibility can vary
• Charging affects different portions of the spectra by different amounts, which can make analysis difficult
• Analysis is destructive

Learn More

Example Outputs Instruments Used How AES Works

• Solid phase
• Must be stable under ultra-high vacuum
• Must be electrically conductive
• Maximum dimensions: 6.5 mm x 6.5 mm x 2.5 mm

This technique utilizes high-energy electron beam as an excitation source resulting in the emission of Auger electrons, whose kinetic energies are characteristic of the elements and chemical states present in the surface of a sample. The emitted auger electrons are picked up by a specialized detector, which scans over an energy range and analyzes the amount of auger electrons at each kinetic energy value. The resulting spectrum allows analysts to quantitatively determine the elemental composition of the surface. The source electron beam can also be finely focused to diameters as small as ~5 nm to create secondary electron and Auger images which are used not only for compositional and topographic analysis but also to locate features of interests. In conjunction with ion beam sputtering, depth profiling can also be done on samples to provide composition as a function of depth as well as layer thicknesses.