fbpx
Select Page

Contamination with Silicone

For further information and pricing, please get in touch with us.

Polydimethylsiloxane (PDMS) is inert, non-toxic and nonflammable and used extensively as a lubricant, in cosmetics, as a food additive [E900] and in sealants.

However, it can break down to silicon dioxide (glass) and form an insulating layer in electronics as well as forming a barrier to adhesion when bonding surfaces – it is also difficult to remove. SIMS can easily detect monolayer quantities of this important industrial contaminant.

Overview

The positive secondary ion spectra below are from an aluminium foil before and after contact with a protective glove. A residue of PDMS from the glove manufacture has transferred to the foil and is clearly visible from the characteristic silicone peaks at m/z = 59, 73 and 147. The aluminium signal itself at m/z = 27 is also significantly attenuated by the coverage of contaminant.

Positive ion Static SIMS of clean aluminium foil before touching with
contaminated glove 

Positive Static SIMS of aluminium foil after contact with contaminated glove

Dynamic SIMS

Depth Profiling

When the ion dose exceeds the static SIMS limit (>1012 ions cm-2) there is sufficient sputtering to uncover deeper layers of the material. This allows the composition to be determined as a function of depth. SIMS depth profiles are most often used to verify layer deposition and investigate diffusion or the effects of surface chemistry, such as corrosion. The extreme sensitivity and excellent depth resolution of SIMS made the analysis of dopant profiles in semiconductors a natural early application of the technique. These pure materials formed the groundwork for robust quantification and today SIMS finds application across a broad range of industries.

Depth Resolution

In the static SIMS case the depth resolution is the uppermost atomic monolayers. In dynamic SIMS, the depth resolution is improved by reducing the impact energy, and therefore the penetration and mixing caused by the bombarding ions such that nanometre features can be resolved.

Positive ion SIMS depth profilePositive ion SIMS depth profi le of a Si/Fe neutron mirror comprising 80 pairs of silicon and iron layers, each layer 1.8nm thick. Analysed using 1.5keV O2+ primary ions with oxygen flooding.

Further Reading

Icon

The crucial role of defect structure in understanding the electrical properties of spark plasma sintered antimony doped barium stannate 1.74 MB 2 downloads

The crucial role of defect structure in understanding the electrical properties of...
Icon

Silicon-doped β-Ga2O3 films grown at 1 μm/h by suboxide molecular-beam epitaxy 1.33 MB 22 downloads

Silicon-doped β-Ga2O3 films grown at 1 μm/h by suboxide molecular-beam epitaxy ...
Icon

Interaction of molecular oxygen ions with copper surface: features of the energy spectra of sputtered and backscattered ions 511.39 KB 16 downloads

Interaction of molecular oxygen ions with copper surface: features of the energy...
Icon

P-type conductivity in Sn-doped Sb2 Se3 2.64 MB 18 downloads

P-type conductivity in Sn-doped Sb2 Se3 ...
Icon

Controlling Li Dendritic Growth in Graphite Anodes by Potassium Electrolyte Additives for Li-Ion Batteries 3.75 MB 39 downloads

Controlling Li Dendritic Growth in Graphite Anodes by Potassium Electrolyte Additives...
Icon

Robust nonfullerene solar cells approaching unity external quantum efficiency enabled by suppression of geminate recombination 1.05 MB 23 downloads

Robust nonfullerene solar cells approaching unity external quantum efficiency...
Icon

Mitigating Structural Instability of High-Energy Lithium- and Manganese-Rich LiNixMnyCoz Oxide by Interfacial Atomic Surface Reduction 4.22 MB 25 downloads

Mitigating Structural Instability of High-Energy Lithium- and Manganese-Rich LiNixMnyCoz...
Icon

Towards x-ray waveguide formation upon ion irradiation of a Co thin film on Si(111) 1,011.83 KB 24 downloads

Towards x-ray waveguide formation upon ion irradiation of a Co thin film on Si(111) ...
Icon

Analysis of useful ion yield for the Mg dopant in GaN by quadrupole—SIMS 1.03 MB 29 downloads

Analysis of useful ion yield for the Mg dopant in GaN by quadrupole—SIMS ...
Icon

Large area visualization of the Li distribution in lithium-ion battery electrodes using plasma FIB and SIMS 384.40 KB 25 downloads

Large area visualization of the Li distribution in lithium-ion battery electrodes...