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Title: Secondary ion mass spectrometry depth profiling of amorphous polymer multilayers using O{sub 2}{sup +} and Cs{sup +} ion bombardment with a magnetic sector instrument

Journal Article · · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films
DOI:https://doi.org/10.1116/1.2172948· OSTI ID:20777054
; ;  [1]
  1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

Thin planar polymer films are model systems in a number of fields, including nano- and biotechnology. In contrast to reciprocal space techniques such as reflectivity or diffraction, secondary ion mass spectrometry (SIMS) can provide depth profiles of tracer labeled polymers in real space directly with sufficient depth resolution to characterize many important aspects in these systems. Yet, continued improvements in characterization methods are highly desirable in order to optimize the trade-offs between depth resolution, mass resolution, detection sensitivity, data acquisition time, and artifacts. In this context, the utility of a magnetic sector SIMS instrument for amorphous polymer film analysis was evaluated using model polymer bilayer systems of polystyrene (PS) with poly(methyl methacrylate) (PMMA), PS with poly(2-vinylpyridine), and poly(cyclohexyl methacrylate) (PCHMA) with PMMA. Deuterium-labeled polystyrene embedded in PS or PCHMA at concentrations ranging from 5% to 20%(v/v) was used as tracer polymer. Analysis conditions for a magnetic sector SIMS instrument (CAMECA IMS-6f) were varied to achieve a depth resolution of {approx}10 nm, high signal/noise ratios, and high sensitivity, while minimizing matrix effects and sample charging. Use of Cs{sup +} and O{sub 2}{sup +} primary ions with detection of negative and positive secondary ions, respectively, has been explored. Primary beam impact energy and primary ion species have been shown to affect matrix secondary ion yields. Sputtering rates have been determined for PS and PMMA using both primary ion species and referenced to values for intrinsic (100) silicon (Si) under identical analysis conditions.

OSTI ID:
20777054
Journal Information:
Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 24, Issue 2; Other Information: DOI: 10.1116/1.2172948; (c) 2006 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
Country of Publication:
United States
Language:
English