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MS: Massenspektrometrie

MS 7: Techniques and New Developments

MS 7.3: Talk

Thursday, April 5, 2001, 17:45–18:00, EB 202

Mass Spectrometry of secondary neutrals with an improved instrument based on electron-gas post-ionization (INA-X) — •Werner Bieck, Paul Ecker, Michael Kopnarski, and Hans Oechsner — Institut fuer Oberflaechen- und Schichtanalytik IFOS GmbH, Universitaet Kaiserslautern, Erwin-Schroedinger-Str. 56, D-67663 Kaiserslautern, Germany

The application of mass spectrometric methods in surface and thin film analysis allows to make use of high detection sensitivities down to the ppb range, and in the case of secondary neutral mass spectrometry SNMS to get reliable and quantitative information about the sample stoichiometry. This contribution describes the design and the operation conditions of a novel SNMS instrument based on electron-gas post-ionization which incorporates recent instrumental developments in order to enhance the analytical capabilities for quantitative surface and in-depth analysis. A modified plasma chamber in combination with optimized r.f.-coupling allows to establish a high density plasma with low power consumption. The ionization efficiency and the current density for sample sputtering is significantly improved in comparison with previous SNMS-instruments. The secondary neutral particle flux is sampled under oblique take-off angle against the surface normal. Various examples demonstrate improved quantification of SNMS and the flexibility of the instrument in the case of industrial analysis work. In addition, some applications to fundamental studies in the field of ion-surface interaction will be presented.