THIN-FILM DEPOSITION BY REACTIVE MAGNETRON SPUTTERING - ON THE INFLUENCE OF TARGET OXIDATION AND ITS EFFECT ON SURFACE-PROPERTIES

The application of X-ray photoelectron spectroscopy (XPS) for the char acterization of deposited thin indium tin oxide (ITO) layers by reacti ve direct-current magnetron sputtering in Ar:O-2 gas mixtures is perfo rmed. The influence of the gas mixture and the sputter-process duratio n on the discharge power and oxidation state of the target implies tha t the target state is an essential parameter for the production of ITO films. For understanding the plasma-surface interaction, the plasma h as been monitored in front of the target and near the substrate by mea ns of Langmuir-probe diagnostics. The internal plasma parameters, name ly n(e) and k(b)T(e), at the target also at the substrate have been de termined as functions of discharge power and radial position. XPS anal yses indicate a ''selective oxidation'' of tin compared to indium as w ell as a change of the surface composition during the sputter process. (C) 1997 Elsevier Science S.A.