AVS 49th International Symposium
    Plasma Science Friday Sessions
       Session PS-FrM

Paper PS-FrM5
Radical Reactions with Organic/Polymeric Surfaces

Friday, November 8, 2002, 9:40 am, Room C-103

Session: Plasma Surface Interactions II
Presenter: J. Torres, Johns Hopkins University
Authors: J. Torres, Johns Hopkins University
C.C. Perry, Johns Hopkins University
S. Bransfield, Johns Hopkins University
D.H. Fairbrother, Johns Hopkins University
Correspondent: Click to Email
Plasmas play an important role in polymer surface modification based on their ability to introduce new functionalities at the interface. Atomic or molecular radicals are often cited as the key species responsible for initiating surface reactions during plasma processing. Due to the wide range of reactive species within a plasma, however, surface reactions of individual species are hard to determine. In our work we report the results of the reactions of O and Cl radicals generated by thermal dissociation of O@sub 2@ and Cl@sub 2@ respectively, with organic thin films and polymers. The present study focuses on the interaction of atomic and molecular oxygen and chlorine with an X-ray modified hexadecane thiols adsorbed on gold using in situ XPS. Oxygen reaction with these hydrocarbon films proceeds in three stages. Initially the reaction dynamics are dominated by the incorporation of new oxygen containing functionalities at the vacuum/film interface. At intermediate O/O@sub 2@ exposures, when a steady state concentration of C-O, C=O and O-C=O groups has been established, the production of volatile carbon containing species, including CO@sub 2@ is responsible for etching the hydrocarbon film. Upon prolonged O/O@sub 2@ exposures, O atoms penetrate to the film/substrate interface, producing Au@sub 2@O@sub 3@ and sulfonate (RSO@sub 3@) species. In contrast, chlorine radicals do not etch the hydrocarbon surface and produce a uniform distribution of CCl and CCl@sub 2@ species in the near surface region. The advantages of employing self-assembled monolayers as models for polymeric interfaces as well as the interaction of oxygen and chlorine radicals with polyethylene characterized by XPS, ATR-IR and AFM will also be presented.