| AVS 65th International Symposium & Exhibition | |
| Applied Surface Science Division | Monday Sessions |
| Session AS-MoM |
| Session: | Quantitative Surface Analysis |
| Presenter: | Alexander Shard, National Physical Laboratory, UK |
| Correspondent: | Click to Email |
The properties of surfaces and interfaces govern the performance of most manufactured items, from advanced electronic devices, medical devices to packaging materials. The chemical analysis of such surfaces underpins the development of new products with better performance, ensures consistency in production and identifies the causes of failure. Commonly used methods, such as XPS and SIMS, can detect elements and chemical species, but also contain information on the amount of material and its distribution. This talk will describe the application of XPS and SIMS in the measurement of surface chemistry, highlighting the wealth of information available and the areas that need attention and development.
The measurement of coating thickness and the identification of defects is of major importance and will be a focus of attention. For thin (<10 nm) oxide films on silicon, XPS has been shown to be the most accurate method for such measurements and relies on a length scale that must be established by comparison with other methods. The applicability of XPS to other materials, non-planar samples and thicker films has improved in recent years and these developments will be described along with the potential use of both the inelastic background shape and HAXPES to extend the information depth, in some cases to more than 100 nm. The use of SIMS to measure surface composition is a particular priority, particularly in organic materials. Recent descriptions of matrix effects have highlighted the potential magnitude of this problem, but also point to methods to mitigate it. Although matrix effects are often taken into account when attempting to perform quantitative chemical analysis, their effects in SIMS images and depth profiles are often ignored but can be of overwhelming importance.
Recent international inter-laboratory studies have demonstrated that there can be significant disparity in the quantitative results reported by laboratories analysing the same materials using these techniques. The major causes of this variability will be discussed and shown to be predominantly due to the use, or misuse, of interpretational algorithms and reference data. The talk will highlight the role of ISO TC201 and VAMAS TWA2 in improving comparability and reproducibility in the results of these analytical methods.