Ultra Low Energy Secondary Ion Mass Spectrometry (ULESIMS)
ULESIMS combines the benefits of conventional SIMS analysis with the ability to investigate shallow structures by using low energy ion bombardment.
Primary ion beams of O2+ or Cs+ with energies in the range 500eV – 2keV, are used to produce high depth resolution profiles over the depth range up to ~200nm. The technique is restricted to very flat surfaces, e.g. semiconductor substrates and glasses, since surface topography has a direct impact on achievable depth resolution.
- High resolution depth profiling from the surface to ~200nm - provides characterisation of layer structures, buried features and interfaces.
- Monitoring of elemental composition with ppm – ppb sensitivity – identification and quantification of dopants and process contaminants.
- Accurate determination of junction depth and retained doseon shallow semiconductor materials.
Typical Applications
- Quantitative depth profiling of dopants and impurities in shallow semiconductor structures e.g. multi-quantum wells
- Temperature-dependent diffusion studies on silicon and SiGe materials
- Investigating process faults in the manufacture of anti-reflective glass coatings.
- In-depth investigation of the wear layer on tribological specimens
- Examination of layer composition in DVD structures
Typical Industries using SIMS
- Semiconductor wafer manufacturers
- Glass
- Photonics
- Solar Energy
- Aerospace
- Automotive.
