Low-energy electron induced resonant loss of aromaticity: consequences on cross-linking in terphenylthiol SAMs

Autor: A. Lafosse, M. Bourdier, Vincent Humblot, Roger Azria, L. Amiaud, J. Houplin, Claire-Marie Pradier
Přispěvatelé: Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2014
Předmět:
Zdroj: ChemPhysChem
ChemPhysChem, Wiley-VCH Verlag, 2014, 16 (3), pp.1050-9. ⟨10.1039/c3cp53023j⟩
ChemPhysChem, 2014, 16 (3), pp.1050-9. ⟨10.1039/c3cp53023j⟩
ISSN: 1463-9084
1463-9076
1439-4235
1439-7641
DOI: 10.1039/c3cp53023j
Popis: International audience; Aromatic self-assembled monolayers (SAMs) can be used as negative tone electron resists in functional surface lithographic fabrication. A dense and resistant molecular network is obtained under electron irradiation through the formation of a cross-linked network. The elementary processes and possible mechanisms involved were investigated through the response of a model aromatic SAM, p-terphenylthiol SAM, to low-energy electron (0-10 eV) irradiation. Energy loss spectra as well as vibrational excitation functions were measured using High Resolution Electron Energy Loss Spectroscopy (HREELS). A resonant electron attachment process was identified around 6 eV through associated enhanced excitation probability of the CH stretching modes ν(CH)(ph) at 378 meV. Electron irradiation at 6 eV was observed to induce a peak around 367 meV in the energy loss spectra, attributed to the formation of sp(3)-hybridized CHx groups within the SAM. This partial loss of aromaticity is interpreted to be the result of resonance formation, which relaxes by reorganization and/or CH bond dissociation mechanisms followed by radical chain reactions. These processes may also account for cross-linking induced by electron irradiation of aromatic SAMs in general.
Databáze: OpenAIRE
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