AVS 45th International Symposium
    Applied Surface Science Division Thursday Sessions
       Session AS-ThM

Paper AS-ThM6
Development of Well Defined Reference Samples for ARXPS Depth Profiling Studies

Thursday, November 5, 1998, 10:00 am, Room 307

Session: Gaede-Langmuir Award Address and Quantitative Surface Analysis
Presenter: B.J. Tyler, Montana State University
Authors: B.J. Tyler, Montana State University
S.J. Hunt, Montana State University
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Quantifying the changes in material composition in the near surface region is important for a wide range of research problems. With inorganic and metallic samples, this information can often be obtained by sputter depth profiling. However, for organic samples, ion sputtering typically destroys the chemical structures of interest before they can be measured. As a result, angle resolve XPS is the preferred method for studying concentration depth profiles (CDP) for polymeric materials and organic thin films. As the interest in organic surfaces has grown, demand for quantitative measures of CPDs for these surfaces has also grown. While qualitative interpretation of ARXPS results is routine, there are many barriers to quantitative calculation of concentration depth profiles (CDPs) from ARXPS results. Many algorithms have been developed for this purpose but determining accurate confidence limits for CDPs, which are calculated with these algorithms, is currently the most significant challenge for quantitative depth profiling with ADESCA. One barrier to assessing the accuracy of CDPs is lack of adequate reference samples. We have evaluated the use of self-assembling monolayers, spin cast polymers, and plasma deposited films for their potential as standards for ARXPS work. The thin films were made on ultra smooth gold and silca substrate. Surface roughness and film thickness have been measured with AFM. ARXPS data for the samples was measured on both a PHI 5600 XPS system and a SSI s-probe. Resulting depth profiles calculated with several algorithms will be presented.