Specific Process Knowledge/Thin film deposition/Deposition of Gold/Adhesion layers: Difference between revisions

The second analysis was performed to understand whether the oxygen was originating from source ii) or iii). A 2-Ti/20-Au/2-Ti/20-Au sandwich structure was deposited and analyzed. Both layers of Ti were partially oxidized: the Ti 2p peak signals (Fig. 5.13a) are present at the same depth together with the O 1s signals (Fig. 5.13b). The O 1s signal in the Ti layer in contact with the Si3N4 substrate has higher intensity than the one of the Ti layer between the Au layers. Hence, the Ti layer in contact with the substrate is more oxidized, which suggests that Ti reacted with water adsorbed on the substrate surface. The conclusion is that the oxygen originated from sources ii) and iii).

Water is present in most thin-�lm deposition systems and it is very di�cult to remove because of its capacity to form hydrogen bonds with many materials. Ti reacts with water and oxygen and forms titanium oxides. Furthermore, the use of the same deposition conditions and of the same type of substrate with respect to Ti and a similar chemical reactivity of Ti and Cr suggest that also the Cr layer gets further oxidized by the water and oxygen molecules present on the substrate surface.