Ion beam with organic surfaces

Interactions of Ion Beams with Organic Surfaces Studied by XPS, UPS, and SIMS... 

J. W. Rabalais, Interaction of ion beams with organic surfaces studied by XPS, UPS, and SIMS, in Photon, Electron, and Ion Probes of Polymer Structure and Properties (D. W. Dwight, T. J. Fabish and H. R. Thomas, eds.), ACS Symposium Series 162, American Chemical Society, Washington, DC, 1981, pp. 237-246. 

These results provide direct evidence that chemical reactions occur and that new chemical bonds are formed during active ion bombardment of organic surfaces. Also, the use of active ions for chemical synthesis via reaction of beams with surface species or by selective "chemical sputtering" is suggested. 

Most early SIMS instruments (such as that described by Lehrle and co-workers) utilized primary-ion beams with fluxes in the l-pA/cm range or higher, which results in ablation of relatively large amounts of ions and neutrals from surface monolayers. These techniques, commonly refered to as sputtering, were used primarily for elemental analysis or for the analysis of relatively small organics. Following the introduction of plasma desorption mass spectrometry, which demonstrated the possibilities... 

In this review results from two surface science methods are presented. Electron Spectroscopy for Chemical Analysis (ESCA or XPS) is a widely used method for the study of organic and polymeric surfaces, metal corrosion and passivation studies and metallization of polymers (la). However, one major accent of our work has been the development of complementary ion beam methods for polymer surface analysis. Of the techniques deriving from ion beam interactions, Secondary Ion Mass Spectrometry (SIMS), used as a surface analytical method, has many advantages over electron spectroscopies. Such benefits include superior elemental sensitivity with a ppm to ppb detection limit, the ability to detect molecular secondary ions which are directly related to the molecular structure, surface compositional sensitivity due in part to the matrix sensitivity of secondary emission, and mass spectrometric isotopic sensitivity. The major difficulties which limit routine analysis with SIMS include sample damage due to sputtering, a poor understanding of the relationship between matrix dependent secondary emission and molecular surface composition, and difficulty in obtaining reproducible, accurate quantitative molecular information. Thus, we have worked to overcome the limitations for quantitation, and the present work will report the results of these studies. 

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