Chemical compositional analysis of homogeneous materials surfaces: Qualitative elemental, iso-topic and molecular information is obtained from the top few monolayers of solid material surfaces, with high mass resolution (5'000-10'000) and ultra-high sensitivity (pmm range). Semi-quantitative and quantitative analysis can also be performed via comparative investigation and reference calibrations, respectively.
Field of applications (non-exhaustive):
- Materials: coatings, polymers, organic thin films, metal alloys, additives, etc.
- Surface properties: contamination, oxidation / corrosion, adhesion, wettability, etc.
- Surface treatments: annealing / curing, environmental exposition, light / ion bombardment, aging processes, etc.
- Life science: pharmaceuticals, bio-compatibility, etc.
Spectrometry example: Curing effect on a silane coating on aluminum
Figure A shows typical ToF-SIMS mass spectra, with on the top that of an as-deposited silane coating on Al and on the bottom that of the same sample after curing. Although the initial chemistry is exactly identical in both cases, one can see large differences in the mass spectra, demonstrating a substantial effect of the curing treatment.
Figure B displays zoom-ins taken from A at specific nominal masses. Note that each nominal mass can display several peaks of different chemical nature and origin, highlighting the importance of having a good mass resolution. After curing, peaks representative for the substrate appear (Al+, Cu+ traces, …), showing that the coating shrunk. Moreover, small silane fragments (Si+, SiHO+, …) became more abun-dant whereas large silane fragments (SiH3O2+, …) almost disappeared. This shows that the curing treatment had the effect of breaking the silane molecules apart.