XPS and XPS valence band characterizations of amorphous or polymeric silicon based thin films prepared by PACVD from organosilicon monomers

Abstract
XPS core levels and XPS valence band spectra were recorded on air-exposed or Ar⁺ sputtered surfaces of a-SiC_x:H and a-SiO_xC_y:H PECVD thin films prepared from various organosilicon precursors with changing the preparation conditions. Their compositions and their XPS valence band spectra were compared with those obtained for SiC, SiO₂ and PDMS conventional polymer. From the calculated compositions and the valence band spectra obtained on air-exposed surfaces, we were able to show the evolutions of the polymeric nature of the films with changing the monomer precursor or the preparation conditions. Furthermore, variations in chemical compositions and valence band spectra induced by Ar⁺ sputtering have been shown and also used to reveal differences between siloxane-like plasma polymers and more inorganic amorphous materials. Informations provided by these investigations were well consistent with other characterization results obtained from XPS core level peak fittings as well as from FTIR and NMR analyses.