| AVS 60th International Symposium and Exhibition | |
| Applied Surface Science | Monday Sessions |
| Session AS-MoA |
| Session: | Analyses Using Novel Ion Beams |
| Presenter: | P. Cumpson, Newcastle University, UK |
| Authors: | P. Cumpson, Newcastle University, UK J. Portoles, Newcastle University, UK A. Barlow, Newcastle University, UK N. Sano, Newcastle University, UK |
| Correspondent: | Click to Email |
Argon Gas Cluster-Ion Beam (GCIB) sources[1,2] are likely to become widely-available on XPS and SIMS instruments in the next few years. Much attention has been devoted to their ability to depth-profile organic materials with minimum damage. What has not been the focus of attention (possibly because it has been very difficult to measure) is the large ratio of sputter rate for organic materials compared to inorganic materials using these sources, and the special opportunities this presents for studies of organic/inorganic interfaces. This large ratio offers a special opportunity to characterise practical organic/inorganic interfaces with near atomic resolution and high sensitivity.
Recently we published argon GCIB sputter yield measurements for 19 polymers[3], using a combination of white-light interferometry and contact masking to provide accurate measurements of sputter crater depth. This technique overcomes the need to form a thin, uniform film of the material of interest, which can be problematic in some cases. These data showed an unexpectedly wide range, the sputter yield of PMMA being more than ten times that of PEEK when using argon ion clusters of around 4 eV/atom, with other polymers being widely distributed between these extremes.
We have extended these measurements to a further 22 materials of wide technological interest, including metals (gold, stainless steel), oxides (Si, Al, Ti oxides), biological materials (collagen, bovine serum albumen, fibronectin etc), and organic materials commonly used in organic electronics and organic photovoltaics, plus a few more polymers. Clearly there is a wide range of sputter yield across this large dataset, with inorganic materials having very low, but measurable, sputter yields. We discuss some systematic trends in these data, and the prospect of developing semi-empirical equations for estimating sputter yield in metals, oxides and molecular solids as well as polymers.
[1] S Rabbani, A M Barber, J S Fletcher, N P Lockyer, and J C Vickerman, Anal. Chem. 83 (2011) 3793.
[2] I Yamada, J Matsuo, N Toyoda, and A Kirkpatrick, Mater. Sci. Eng. R. 34 (2001) 231.
[3] Peter J. Cumpson, Jose F. Portoles and Naoko Sano, J. Vac. Sci. Technol. (2013) A 31, 020605