Nanostructured TiO x film on Si substrate: Room temperature formation of TiSi x nanoclusters

We present a morphologic and spectroscopic study of cluster-assembled TiO x films deposited by supersonic cluster beam source on clean silicon substrates. Data show the formation of nanometer-thick and uniform titanium silicides film at room temperature (RT). Formation of such thick TiSi x film goes beyond the classical interfacial limit set by the Ti/Si diffusion barrier. The enhancement of Si diffusion through the TiO x film is explained as a direct consequence of the porous film structure. Upon ultra high vacuum annealing beyond 600 °C, TiSi2 is formed and the oxygen present in the film is completely desorbed. The morphology of the nanostructured silicides is very stable for thermal treatments in the RT-1000 °C range, with a slight cluster size increase, resulting in a film roughness an order of magnitude smaller than other TiO x /Si and Ti/Si films in the same temperature range. The present results might have a broad impact in the development of new and simple TiSi synthesis methods that favour their integration into nanodevices. © 2010 Springer Science+Business Media B.V.