Published online by Cambridge University Press: 28 February 2011
The reactivity of XeF2 and CF3 on thermally grown SiO2 surfaces has been investigated. CF3 radicals were generated by infrared multiple-photon dissociation of C2F6 using a pulsed CO2laser. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical state of the surface after exposure to the gases. Both CF3 and XeF2 are relatively inert to annealed SiO2 surfaces.- Ion damaged surfaces are much more reactive. Implications for ion enhancement of etching are discussed. XPS spectra reveal fluorine, from XeF2 bonded to both silicon and oxygen. The CF3 radical appears to undergo little dissociation upon chemisorption on SiO2.