| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Energy Harvesting & Storage | Wednesday Sessions |
| Session EH-WeM |
| Session: | Characterization of Materials for Energy Applications I |
| Presenter: | David Surman, Kratos Analytical Inc. |
| Authors: | D. Surman, Kratos Analytical Inc. J. Counsell, Kratos Analytical Ltd., UK S. Hutton, Kratos Analytical Ltd., UK H. Brannon, Kratos Analytical Ltd., UK |
| Correspondent: | Click to Email |
Over the last several years massive Argon gas cluster ion sources as accessories for sputter depth profiling of organic materials have increased in popularity. These sources utilize Argon cluster ions formed via adiabatic isentropic expansion of Argon gas into a vacuum followed by subsequent electron impact ionization and cluster size selection. In ideal cases the aforementioned massive cluster ions efficiently sputter the surface of organic materials revealing undamaged subsurface structure for analysis. More recently, developments in the technology have expanded the use of these sources to allow for the sputtering of inorganic materials.
Advanced software controlled ion sources and flexible sample handing equipment allow a wide range of experimental conditions to be routinely employed during sputter depth profiling with these massive Argon clusters. In this study we have investigated a variety of parameters such as incident ion energy and cluster size distribution on the effectiveness of the sputtering process and the degree of chemical damage that is induced using X-ray Photoelectron Spectroscopy (XPS) as the monitor. A range of both organic and inorganic materials have been analysed. It has been observed that for most organic materials large cluster sizes with a medium beam energy (typically less than 10kV) are very effective for sputtering with no observable chemical damage. This is in contrast to sputtering of inorganic materials where typically high beam energies (greater than 10keV) and small cluster sizes are required for effective sputtering. The identification of a minimum partition energy for sputtering will be discussed. In addition, it will be demonstrated that, although preferential Oxygen sputtering can be observed on many oxides resulting in the formation of reduced chemical states, this effect is substantially reduced when compared to the use of monoatomic Ar ions.