Dynamic Secondary Ion Mass Spectrometry

Dynamic Secondary Ion Mass Spectrometry is the ideal technique to use if you need an elemental depth profile of your sample with ppm to ppb detection limits up to a depth of 10 µm.  D-SIMS is most commonly used to perform in-depth impurity analysis looking at dopants or low level contamination on a range of hard materials from semiconductors, metals to insulators.

How SIMS works – your sample is sputtered with a primary ion beam (oxygen or cesium), sputtering atoms from the surface. A portion of the atoms leaving the surface are ionized. These ions are extracted into a mass spectrometer and separated by their mass/charge ratio and counted. Since you are removing atoms over time with sputtering, time is related to depth. A plot of sputter time vs. ion counts can be converted to depth vs. concentration.

This is an accordion element with a series of buttons that open and close related content panels.

Instrumentation Available

Key Attributes

  • Elements detected H-U (depending on instrument configuration)
  • Detection limit: ppm – ppb
  • Depth profiling from few hundred nm to 10 µm

Strengths

  • Depth profiling
  • Parts per million to parts per billion detection limit
  • Analysis of insulators and conductors
  • High detection sensitivity
  • nm depth resolution possible
  • 3D imaging is possible

Limitations

  • Destructive
  • Very specific standards required for accurate quantification
  • Soft material samples (polymers, biologicals) are easily damaged, limiting usefulness
  • No molecular information
  • Samples must be flat
  • Samples need to be a minimum of 1 x 1 cm
  • Samples must be vacuum compatible

Applications

  • Depth profiling of metals, semiconductors and insulators
  • Bulk composition measurements of hard materials
  • Trace element and contamination analysis

Additional Reading

https://youtu.be/fnkXNaNekaY