AN X-RAY PHOTOELECTRON SPECTROSCOPIC INVESTIGATION INTO THE CHEMICAL-STRUCTURE OF DEPOSITS FORMED FROM HEXAMETHYLDISILOXANE OXYGEN PLASMAS/

The effect of oxygen addition to microwave-sustained plasmas of hexame thyldisiloxane (HMDSO) has been investigated. Attention was directed t o the solid products formed on aluminium substrates (plasma deposits). To enable a quantitative analysis of these, X-ray photoelectron spect roscopy (XPS) of standard silicon-containing materials was carried out . When suitable charge correction is applied to the XP spectra of HMDS O/O-2 plasma deposits, a number of very clear trends emerge. From chan ges in elemental composition, core line binding energies (Si 2p, C 1s, and O 1s) and widths, we show how oxygen addition to the plasma affec ts the chemical nature of the plasma deposit. The data reported also p rovide (some limited) information on the reactions taking place in the plasma.