Rasmus Havelund oral presentation (OB1-Thu1-1-1)
Accurate organic depth profiling and 3D imaging using SIMS in single beam, dual beam and dual spectrometer modes
National Physical Laboratory, Hampton Road, TW11 0LW Teddington, United Kingdom
The development of gas cluster ion beams has transformed the ability for depth profiling of organic materials using SIMS. The combination of the excellent depth resolution and detailed molecular information is highly valuable and not offered by any other technique. However, improved quantification and chemical identification are needed to fully exploit the analytical power. This talk addresses these issues.
Carefully prepared organic reference multi-layers have in a number of studies been used to measure sputtering yields, depth resolutions, and, recently, the matrix effect in binary molecular mixtures. These are important parameters for quantitative depth profiling. Here, the ability to accurately measure the thickness of organic layers and the depth of interfaces is evaluated. A detailed analysis of the critical role of the matrix effect is provided.
Recent advances in the mass spectrometer design are beginning to have significant impact in SIMS. These include the ability for high duty cycle quasi DC sputtering with MS/MS capability, linear ToF MS/MS and a new hybrid time-of-flight Orbitrap instrument called the 3D OrbiSIMS (with high-resolution MS/MS).
The 3D OrbiSIMS instrument has a high degree of flexibility with operating modes for spectroscopy, depth profiling (1D), 2D imaging and 3D imaging. Here, we use the instrument’s ability to operate in single beam mode, dual beam mode and also in combination with dual spectrometer mode to study important parameters for 3D imaging using the well characterised NPL organic reference multi-layers. These include the dynamic range, depth resolution and sensitivity.
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 Fletcher, J. S. & Vickerman, J. C., “A new SIMS paradigm for 2D and 3D molecular imaging of bio-systems”, Anal Bioanal Chem 396, 85-104 (2010)
 Fisher, G. L. et al., “A New Method and Mass Spectrometer Design for TOF-SIMS Parallel Imaging MS/MS”, Anal Chem 88, 6433-6440 (2016)