AVS 50th International Symposium
    Applied Surface Science Tuesday Sessions
       Session AS-TuM

Paper AS-TuM6
SF5+ Ion Beam Damage of Poly(Acrylates) Studied using Time of Flight Secondary Ion Mass Spectrometry

Tuesday, November 4, 2003, 10:00 am, Room 324/325

Session: Image Analysis and Polymer Characterization
Presenter: M.S. Wagner, National Institute of Standards and Technology
Authors: M.S. Wagner, National Institute of Standards and Technology
G. Gillen, National Institute of Standards and Technology
Correspondent: Click to Email
Recent advancements in instrumentation for Secondary Ion Mass Spectrometry (SIMS) have focused on the development of polyatomic primary ion sources. Polyatomic ions have been shown to increase the secondary ion yields of molecular ions from organic materials when compared with monoatomic ions of similar mass. Furthermore, some polymer films, notably poly(methyl methacrylate) and poly(ethylene glycol), display the unusual characteristic of maintaining their characteristic molecular ion signals after extended polyatomic ion bombardment. This study focuses on the effect of the chemical structure of the polymer on its stability under extended SF5+ ion bombardment. The damage of spin cast polymer films by 5 keV SF5+ was studied using positive and negative ion static Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). A class of poly(acrylate) polymers with systematic changes to the monomer structure were investigated to determine the effects of polymer structure on the stability of their characteristic ion signals under 5 kV SF5+ bombardment in the ion dose range from 2.5 x 10@super 13@ - 5 x 10@super 14@ SF5+ ions/cm@super 2@. Preliminary results have shown that poly(methacrylic acid) and poly(methyl methacrylate) were stable under extended SF5+ bombardment while poly(methyl acrylate) was not, suggesting a role for the methyl group on the central carbon in the stabilization of the polymers under SF5+ bombardment. Monte Carlo calculations using the SRIM software@footnote 1@ show that the penetration depths of fluorine and sulfur ions in these polymers were the same despite the different damage characteristics, highlighting the importance of the chemical structure of the polymer on its stability under polyatomic ion bombardment. This study describes the breadth of applicability of SF5+ sputtering to the depth profiling of polymer films. @FootnoteText@ @footnote 1@ More information on this program can be found at http://www.srim.org.