AES：Auger Electron Spectroscopy
Features
AES is a surface analysis tool which yields detailed information about the sample surface:
- Qualitative and quantitative analysis of solid materials down to a depth of several nm.
- Micro-area analysis (from tens of nanometers to several micrometers).
- Depth and lateral analysis of principal component elements.
- Analysis of the oxidation and metal state of some elements, such as Si and Al.
- Identification and localization of region of interest (ROI) via a built-in SEM system.
Application Examples
- Evaluation of inter-layer metal diffusion in metal multilayer films.
- Oxide film evaluation of various metals.
- Compositional evaluation of special shapes (spheres, inner walls, etc.).
- Elemental distribution and deterioration evaluation of battery materials.
- Evaluation of foreign particles of several tens of nanometers to sub-micrometers on devices.
- Evaluation of interlayer defects using cross-sectional processing.
- Evaluation of layer structure and element distribution of fractured cross sections.
Principle
AES detects the energy spectrum of Auger electrons generated by electron beam irradiation. Since the Auger electron energy depends on the element, the elements constituting the sample can be identified. The relative signal strengths yield information about the composition.
Process of Auger electron generation
When an atom in the ground state is irradiated with an electron beam (① in Fig. 2), the inner shell electrons are excited and there is a probability of ionizing the atom, resulting in vacancies in the inner shell (② in Fig. 2). The state with vacancies in the inner shell K is energetically unstable so outer shell electrons transition to the inner shell (③ in Fig. 2). At that time, the difference in energy between the pre- and post-transition states is passed on to electrons bound in the pre-transition orbit (④ in Fig. 2). The electrons that gain energy are released into vacuum as Auger electrons.(⑤ in Fig. 2). The excess energy generated in ③ is either emitted as characteristic X-rays or Auger electrons. Analysing the energy of the emitted Auger electrons gives information about the element.
Data examples
Data delivery formats
- PDF file : Spectral and depth profile graphs, surface distribution and SEM images.
- Excel file : Numerical data (Auger spectra, depth profile).
Specifications
Items for enquiries
- Purpose and contents of measurement
- Sample information
- Number of samples, and availability of preliminary samples.
- Shape, layer structure, film thicknesses, patterns and surrounding insulation (if any), dimensions and locations of foreign substances, lateral and depth regions and elements (especially in the depth direction) of interest , permission for destructive testing.
- Handling instructions.
- Preferred due date for preliminary analysis report.
- Due date for delivery of final report.
Caution
The following sample properties may adversely affect the analysis:
- Charging by insulators.
- Significant surface contamination.
- Large surface roughness.
- Excess outgassing that reduces the degree of vacuum in the chamber.
［AES］オージェ電子分光法の分析事例はこちらからご覧ください。