Modification of polymeric and organic surfaces by low-energy atomic and polyatomic ions.

摘要

Low-energy (1-1000 eV) ion beams interacting with solid surfaces have important implications for materials processing. The surface modification of polymeric and organic materials is often a requirement for various technological applications. Ions as directed beams or in plasmas are currently used for surface modification of these organic surfaces. However, a lack of fundamental understanding of the processes involved is impeding the development of these technologies. This thesis describes a series of experimental and computational investigations of selected ion-surface pairs to elucidate the processes leading to surface modification of polymeric and organic materials. X-ray photoelectron spectroscopy probed the 50-140 eV Ar{dollar}sp+{dollar} ion induced modification of a 2-(trimethoxysilyl) ethyl-2-pyridine monolayer on silicon. This study demonstrated the potential of using low energy ions in conjunction with a selective metallization technique for patterning self-assembled monolayers for microelectronic fabrication. The ion induced desorption of adsorbates is studied by comparing the relative desorption cross-sections for an NH{dollar}sb3{dollar}/CO/Ni(111) system by hyperthermal atomic (Xe{dollar}sp+{dollar}) and polyatomic (SF{dollar}sb5sp+{dollar}) ions. Comparison with results using the Monte Carlo code, Tridyn, is used to elucidate the mechanisms of the sputtering events and to rationalize the observed enhancement in the sputter yields for the polyatomic ion. The polyatomic effect on surface modification is further explored by comparing the chemical modification induced by SF{dollar}sb5sp+{dollar} and {dollar}rm Csb3Fsb5sp+{dollar} ions on polystyrene. The ion kinetic energy range is determined at which the molecular nature and identity of the ions become important in the fluorination process. The implications of these results to plasma processing are discussed.