Growth of primary and secondary amine films from polyatomic ion deposition

Amine-containing organic films are deposited onto silicon substrates from mass-selected beams of 5-200 eV Si2NC8H19+ (silazane) and 15-100eV C3H6N+ (allylamine) ions produced by electron impact ionization of 1,3-divinyltetramethyldisilazane and allylamine. Silazane films are also deposited onto aluminum substrates. These ion-deposited films are analysed directly and/or after air exposure by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Chemical derivatization prior to XPS analysis is utilized to distinguish primary and secondary amine groups in the films from non-amine nitrogen. Primary amines are absent in silazane films. Secondary amine containing films form at low silazane ion energies whereas the higher ion energies lead to formation of more inorganic, silico-carbo-nitride-like films. The ion energy trend is similar for films from allylamine ions, except for the fact that both primary and secondary amines are detected. The primary amines from allylamine ions survive film ageing in air for periods of several days. Ion-induced film-substrate reactions are observed for silazane films. (C) 2004 Published by Elsevier Ltd.