XPS analysis on SiO2 sol-gel thin films

The X-ray Photoelectron Spectroscopy has been applied to study the composition and the electronic structure of thin SiO2 films prepared using the sol-gel technique on silicon substrates. Samples prepared using different amount of tetraethoxysilane and methyltriethoxysilane have been annealed at various temperatures. The valence band, the Si 2p and KL(23)L(23) Auger features have been followed as a function of the preparation conditions. The Si Auger parameter has been used to determine the attendance of different C-H and OH groups. The presence of Si-C bonds, observed in the valence band spectra, strongly decreases as the annealing temperature grows, showing the loss of methyl groups.