Developing analytical solution for industry and academia
Modern life is characterised by continuous development and technological change. The capacity for understanding, controlling and taking advantage of new ideas is essential. As a result, analytical instrumentation has to expand its performance to fulfil current and future analytical demands.
IONTOF provides analytical solutions for many of today´s high-tech industries. Our mission is to develop our instrumentation technique and expand their potential for future applications. Considerable research effort as well as close co-operation with our customers will continue to create new possibilities, thus keeping our instruments at the leading edge of technology.
Paints and Coatings
Areas of Applications
Trace Metal Detection
The detection and quantification of trace metals is an important analytical task in the semiconductor industry.
TOF-SIMS is able to detect all elements (even the light ones) with isotope sensitivity. High mass resolution, high mass accuracy and good signal to noise ratio allow sensitivities down to 1E7 to 1E9 atoms/cm2.
The technique can be applied to patterned wafers and even to the backside of a wafer without loss in sensitivity.
Quantification is done by using external standards with an accuracy comparable to other techniques such as TXRF or ICP-MS.
Details of a spectrum of a Silicon wafer surface. High mass resolution and accuracy allow the unambiguous identification of trace metals
Typical application areas of ultra-shallow depth profiling are the classical SIMS tasks in the semiconductor industry. Here, mainly the profiling of low energy implants of boron, phosphorous and arsenic are of interest, but also the profiling of ultra-shallow gate oxides and the detection of trace elements within the native oxide requires excellent sensitivities for low energy sputtering.
The parallel detection of all masses allows the measurement of the also implanted F as well as of metal contaminants e. g. Aluminium at the same time, thus making the technique well-suited for screening purposes.
100 keV asenic implant, 1000 V Cs sputtering, 15 keV Bi analysis
The monitoring of organic contaminants becomes more and more important for the semiconductor industry. TOF-SIMS provides detailed inorganic and organic information about the wafer surface.
Possible sources of contaminants are:
Process Chemicals (photoresists, cleaning agents (POX, SOX, …)
OLED technology is used in portable devices such as mobile phones, portable music players, car radios etc.
One of the biggest technical problems left is the limited lifetime of the organic materials.
It is therefore important to study the chemistry of the different organic layers.
TOF-SIMS spectrometry imaging and depth profiling using the gas cluster source enables these kind of studies.
3D analysis of an OLED pixel using argon cluster sputtering
Ultra-thin Film Analysis
In the semiconductor industry ultra-thin films such as diffusion barriers and high-k layers are more and more often manufactured by atomic layer deposition (ALD).
The example shows five different LEIS spectra taken after an increasing number of deposition cycles of WNXCY on silicon.
By monitoring the decreasing silicon and the increasing tungsten signal it can clearly be seen that 40 ALD deposition cycles are necessary for a closed layer of WNXCY.
The peak shape on the low-energy side of the tungsten WNXCY SiOX surface peak also shows the growth of multiple layer islands before reaching full coverage.
By measuring the energy loss the minimum and maximum thickness of the film can be calculated with sub-nm precision. Growth modes can be determined following the development of the in-depth signals with an increasing number of deposition cycles.
LEIS spectra taken after an increasing number of ALD cycles of WNXCY on silicon
WNXCY and SiOX coverage as a function of the number of deposition cycles
Surface spectrum of a Fluorinated Polyether
Many technological fields require the understanding and processing of the molecular structure of surfaces.
Static SIMS is the ideal analytical technique because it detects both large, complex molecular ions and fragment ions with ultimate sensitivity to provide detailed structural information.
The excellent transmission of our TOF-SIMS analysers, the high mass range and advanced cluster ion sources make our TOF-SIMS instruments the perfect tool for organic materials such as polymers, biomaterials and pharmaceuticals.
Spectrum of a high-tech lubricant (fluorinated polyether) showing the oligomer distribution in the high mass range.
Discolourations on polymers are often caused by phase separation of the material's components. This blooming can be caused by incompatibilities of the used additives with the polymer or other ingredients.
The example shows secondary ion images of crystalline blooming on polypropylene (PP).
Paints and Coatings
Defect Analysis of Paint
Coatings are of increasing importance for many industrial products for reasons of decoration as well as stability.
There is a technological challenge caused by various substrates used (e.g. metals, glass, polymers), because different classes of material are applied as coatings, and because many products are reshaped after the coating step.
Crater formation and adhesion problems are therefore among the most common analysis requests.
Car Paint Cross-section
The example shows the chemical composition of a paint cross-section.
The images show the distribution of the different SO3 and Cl representing the different layers as well as the allocation of the imbeded hindered amine light stabilizers (HALS) and UV adsorbers (UVA).
HALS + UVA
Duchenne Muscular Dystrophy Lipids
The ability of TOF-SIMS to image individual molecular compounds in order to obtain their detailed spatial arrangement was used to study the degenerative/regenerative processes in the muscles of a dystrophin-deficient model mouse.
The specific distribution of different substances (fatty acids, vitamin E, triglycerides, phosphatidic acids, coenzyme Q9 and chlorine) were imaged from untreated mouse leg sections.
The images of individual substances show their distribution over the section.
A concentration of chlorine is found in the destructured zone, known from other analyses to be regenerating. The chlorine is probably combined with sodium and potassium also found in this zone.
Fatty acids and triglycerides are located mainly in the blue intermediate zone, vitamin E, phosphatidic acids, and coenzyme Q9 are found in both the blue and green intermediate zones.
But there is much more vitamin E and coenzyme Q9 in the green zone than in the blue, and it is suggested that these high accumulations mark oxidation stress and inflammatory reactions which can lead to muscle necrosis. Both zones are under oxidation stress and the green zone can be considered degenerative.
It was also found that the ratio of fatty acids, palmitic acid to palmitoic acid, and the ratio of stearic acid to oleic acid varied between the zones.
Overlay: Cl, Oleic Acid, Coenzyme Q9
The 500 x 500 µm2 overlay image of several ion maps of the mouse leg section shows an apparently healthy zone on the right (dark red/black), a destructured zone (red) on the left corresponding to that seen in the optical image, and two intermediate zones (green and blue)
The data was provided by Dr A. Brunelle, ICSN-CNRS, Gif-sur-Yvette, France. The reference is: David Touboul, Alain Brunelle, Frédéric Halgand, Sabine De La Porte and Olivier Laprévote 2005, Journal of Lipid Research, Vol. 46, 1388-1395, July 2005
The example below shows mass resolved secondary ion images from a tablet cross section.
This technique can be used to determine the distribution of the different ingredients, including the drug itself, within the tablet.
Correlation analysis of a tablet cross section showing the lateral distribution of various components
Asthma Drug Salbutamol
The asthma drug Salbutamol is commercially produced as a coating on micron-sized sugar beads and packed in an aerosol container.
A large area of many beads was imaged using Bi3++ (illustrated on the left) and the image of one bead was enlarged (right).
The distribution of the molecular ion of Salbutamol, mass 240 u, on the bead surface is clearly visible. The pixel size in the image is 100 nm x 100 nm2, and the mass spectrum from the selected pixel shows significant intensity for the Salbutamol molecular ion peak (20 counts detected).
Calculation shows that the amount of Salbutamol in this pixel area was in the range of 2 x 10-20 mol.
Salbutamol Field of view 52.7 x 52.7 µm2
Salbutamol: Field of view 9.5 x 9.5 µm2
Mass spectrum reconstructed from a single image pixel (100 x 100 nm2)
Salbutamol (M+H)+: 2.1E5 counts
Failure Analysis of an Optical Device
The continuous development of the sputter performance has opened new fields for time-of-flight dual beam depth profiling. Sputter rates in the range of 10 µm/h can be obtained making depth profiling in the µm range possible.
The pulsed nature of the technique makes it also well-suited for the profiling of insulators.
This feature in combination with the parallel mass detection makes TOF-SIMS dual beam depth profiling best suited for the analysis of unknowns (e. g. reverse engineering, failure analysis, interface analysis, etc.).
The example below is typical for failure analysis. The two profiles were acquired on one “good” and one “bad” sample.
The differences in the layer structure and thickness can clearly be seen. This renders it possible to draw conclusions about the cause of the failure.
Profile through the surface layer of a "good" optical device
Profile through the surface layer of a "bad" optical device
Ink Line Cossing
The analysis of different inks on paper can be of great value. Especially if it is necessary to determine e. g. which signature on an important document was applied first or whether parts of a document have been changed after the document was signed.
Different inks normally show different characteristic SIMS signals. If the signatures overlap TOF-SIMS imaging can determine the sequence of application.
The example shows a large area scan from a document with print and two crossing signatures. The TOF-SIMS images of the two signatures clearly show that signature 2 was applied before signature 1.
Most paper surfaces are treated to obtain special surface properties. The treatment results in different lateral distributions of certain organic and inorganic surface species. These surface modifications can be investigated using TOF-SIMS.
The example shows the lateral distribution of certain organic and inorganic species on a paper surface.
Total Ion Image
Diffusion through a Polycrystalline Metal Oxide
One major advantage of TOF-SIMS is the opportunity to combine high lateral and high depth resolution.
In the so-called dual beam depth profiling it is possible to optimise the analysis beam and the sputter beam independently and measure 3D chemical profiles.
The example shows a 3D analysis of a diffusion process though a polycrystalline metal oxide of La0.8 Sr0.2 Ga0.8 Mg0.2 O2.8
The 3D images show that the diffusion of Cr, Fe and Y is not homogenous throughout the whole sample.
Post analysis data reconstruction allows for the separation of the different areas within the 3D image.
Hence, different profiles from areas of fast and slow diffusion can be reconstructed to provide detailed information about the diffusion process.
Reconstructed depth profiles from different regions of interested (ROI) showing the in-depth distribution of Cr, Fe and Y.
3D overlay image of Cr, Fe (red) and Ga (blue)
For catalysis the characterisation of the top surface layer of atoms is essential and the Qtac100 is the perfect tool for this application. In this example it is used to study sub-monolayer coverages of Te, Nb and Sb oxides on Mo-V-O.
This multi-component catalyst is used for the conversion of propane feedstock to acrylic acid and acrylonitrile, intermediary chemicals for the production of clothes, home furnishings, paints, adhesives etc.
The results show the surface composition of Mo-V-M-O (M = Te, Nb, Sb) catalysts. A study of different surface concentrations of Te, Nb and Sb reveals which combination gives the optimum selectivity and reaction rates.
Energy spectra showing the elements present in the top atomic layer of a Mo-V-Te-O catalyst. The detail spectrum on the right shows a higher resolution spectrum acquired using Neon instead of Helium ion scattering.
Zn/Cu Surface Ratio after different Catalyst Reduction Processes
The example below shows the Zn/Cu ratio measurement after different reduction treatments. The reduction process with CO/CO2/H2 treatment at a temperature of 573 K gives the best performance.
This leads to the assumption that a surface concentration of Zn results in a higher performance of the catalyst.
In-depth Zn/Cu atomic ratio distribution after different reduction processes