Particle – matter interactions for ion microscopy

Optimization of sensitivity and quantification in SIMS

Secondary Ion Mass Spectrometry (SIMS) is a well-established and extremely powerful technique for the chemical analysis of surfaces and thin films. Its main advantages are:

its excellent sensitivity
its high dynamic range
its good mass resolution
its ability to distinguish between isotopes.

The use of cesium can dramatically increase the sensitivity of the analysis. We have therefore developed an add-on Cs deposition system allowing the sample surface to be coated with Cs prior to or during SIMS analysis for the purpose of optimizing analytical performances. This system presents several advantages, including:

increased sensitivities in the negative secondary ion mode (ionization probabilities of 100% for elements with high electron affinities)
minimization or elimination of the matrix effect in the negative secondary ion mode
optimization of the sensitivities in the MCsx+ mode for efficient elimination of the matrix effect.

Contact: Patrick PHILIPP

Investigation of particle – matter interactions

For ion-beam-based microscopy, the development of new instruments, methods and applications requires the control of processes and mechanisms like particle sputtering and ionization. We are therefore investigating particle – surface interactions by:

experimental studies
numerical simulations:
- Monte Carlo based on binary collision approximation
- Molecular Dynamics (MD) simulations
- Density Functional Theory (DFT) calculations.

The different aspects that are explored include: