| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Tuesday Sessions |
| Session AS-TuP |
| Session: | Applied Surface Science Division Poster Session |
| Presenter: | Simon Hutton, Kratos Analytical Limited, UK |
| Authors: | S.J. Hutton, Kratos Analytical Limited, UK T. Bendikov, Weizmann Institute of Science, Israel K. Macak, Kratos Analytical Limited, UK W. Boxford, Kratos Analytical Limited, UK S.C. Page, Kratos Analytical Limited, UK S.J. Coultas, Kratos Analytical Limited, UK C.J. Blomfield, Kratos Analytical Limited, UK J.D.P. Counsell, Kratos Analytical Limited, UK |
| Correspondent: | Click to Email |
Angle resolved X-ray photoelectron spectroscopy (ARXPS) is a widely used technique for investigating the depth distribution of species over the first few nanometres of the sample surface. An important property of the technique is that it is non-destructive; the sample is not damaged during the measurement process. This is in contrast to sputter depth profiling where an ion beam removes the surface layer to reveal the underlying material. A major shortcoming of the ARXPS technique is that it provides information only from the surface region of the material. It is limited to the maximum escape depth of the photoelectrons generated during measurement. This limitation is not shared by sputter depth profiling, which can delve deep into the material by employing multiple sputter / analysis cycles.
Chemical damage of the analysed material is an ever present consideration during sputter profiling. One method of reducing this chemical damage is to vary the nature of the sputtering ion. This has proved very successful for organic materials and thin films where massive gas cluster ions have found widespread use. We have previously demonstrated the successful use of massive Ar clusters to sputter depth profile through multi-layer organometallic thin films [1]. In this study we compare the results of non-destructive ARXPS measurements with ultra-shallow sputter depth profiling using massive Ar cluster ions on similar multi-layer organometallic thin films.
The films consist of two well defined and iso-structural osmium and ruthenium polypridyl complexes. These complexes are deposited from solution in a sequence-dependent assembly regime leading to self-propagating molecular assemblies with distinct internal interfaces and composition. [2] The films were assembled on indium tin oxide (ITO) coated glass slides. ARXPS data was collected by tilting the sample with respect to the analyser / X-ray source. The results were processed using a maximum entropy method software package developed specifically for this type of application [3].
Shallow sputter profiles through the thin films were achieved using massive Ar cluster ions with approximately 2000 Ar atoms per cluster. Ion acceleration voltages were kept low to ensure a very low energy per Ar atom and hence limit the sputtered region to the sample surface.
[1] S. Hutton, T. Bendikov, W. Boxford, S. Page, J. Counsell, A. Roberts, C. Blomfield, S. Coultas, AS-THP3 AVS 62nd International Symposium & Exhibition.
[2] G. de Ruiter, M. Lahav, G. Evmenenko, P. Dutta, D. A. Cristaldi, A. Gulino and M. E. van der Boom, J. Am. Chem. Soc. 2013, 135, 16533-16544.
[3] K. Macak, Surf. Interface. Anal. 2011.