Energy Dispersive Spectroscopy (EDS)

Energy dispersive spectroscopy (EDS) identifies the elemental composition of materials imaged in a scanning electron microscope for all elements with an atomic number greater than boron.  Most elements are detected at concentrations on the order of 0.1 percent.

Applications: EDS applications include:

  • Materials evaluation and identification
  • Contaminants
  • Elemental diffusion profiles
  • Glassivation phosphorus content
  • Multiple spot analysis of areas from 1 micron to 10 centimeters in diameter
  • Failure analysis
  • Contamination identification
  • Unknowns identification
  • Stringer location and identification
  • Quality control screening
  • Material verification
  • Plating specification and certification

Principle of Operation

As the electron beam of the SEM is scanned across the sample surface, it generates X-ray fluorescence from the atoms in its path.  The energy of each X-ray photon is characteristic of the element that produced it.  The EDS microanalysis system collects the X-rays, sorts and plots them by energy, and automatically identifies and labels the elements responsible for the peaks in this energy distribution.

Typically EDS data are compared with either known or computer-generated standards to produce a full quantitative analysis showing the sample composition.

Data output includes plots of the original spectrum, showing the number of X-rays collected at each energy.  Maps of element distributions over areas of interest and quantitative composition tables can also be produced.