John G. Gillen, Albert J. Fahey, M Wagner, Christine M. Mahoney
Thin monolayer and bilayer filsm of spin cast poly(methyl methacrylate) (PMMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(lactic) acid (PLA) and PLA doped with several pharmaceuticals have been analyzed by dynamic SIMS using SF5+ polyatomic primary ion bombardment. Each of these systems exhibited minimal primary beam-induced degradation under cluster bombardment allowing molecular depth profiles to be obtained through the depth of the film. By combing secondary ion imaging with depth profiling, 3-dimensional molecular image depth profiles have been obtained from these systems. In another approach, bevel cross sections are cut in the samples with the SF5+ primary ion beam to produce a laterally magnified cross section of the sample that does not contain the beam-induced damage that would be induced by conventional ion beam FIB cross sectioning. The bevel surface can then be examined using cluster SIMS imaging or other appropriate microanalysis technique.
Applied Surface Science
beam-induced damage, cluster bombardment, depth profile, secondary ion mass spectrometry