RESEARCH PAPER Nanostructured TiO x film on Si substrate: room temperature formation of TiSi x nanoclusters Mirco Chiodi • Emanuele Cavaliere • Iskandar Kholmanov • Monica de Simone • Oumar Sakho • Cinzia Cepek • Luca Gavioli Received: 29 July 2009 / Accepted: 27 December 2009 Ó Springer Science+Business Media B.V. 2010 Abstract We present a morphologic and spectro- scopic study of cluster-assembled TiO x films depos- ited 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, TiSi 2 is formed and the oxygen present in the film is completely desorbed. The morphology of the nano- structured 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. Keywords TiSi x Á Cluster Á Cluster-assembled TiO x Á Silicide Á Nanostructure Á Thin film Á Synthesis Introduction Nanostructured systems are at the edge of material physics research (Moriarty 2001; Hiramoto et al. 2006), with physical and chemical properties that make them extremely promising for industrial appli- cations such as protective coatings (Wang et al. 2008; Chen 2005), microelectronics (Ho et al. 2008), biomedicine (Ebron et al. 2006), catalysis (Fujishima and Honda 1972; Linsebigler et al. 1995). In this context, nanoscaled titanium silicides are currently investigated as materials for next generation’s devices, such as sensors, solar cells, logical circuit devices, field emitters (Zhou et al. 2009; Lin et al. 2008; Zou et al. 2008; Chang et al. 2009), thanks to the low resistivity, thermal stability and good adhe- sion to silicon substrates (Zhang and O ¨ stling 2003). M. Chiodi (&) Á E. Cavaliere Á I. Kholmanov Á L. Gavioli Dipartimento di Matematica e Fisica, Universita ` Cattolica del Sacro Cuore di Brescia, Via Musei 41, Brescia 25121, Italy e-mail: chiodi@dmf.unicatt.it M. Chiodi Á M. de Simone Á O. Sakho Á C. Cepek Á L. Gavioli CNR-INFM, Laboratorio Nazionale TASC, SS-14, Km 163.5, Trieste 34012, Italy I. Kholmanov CNR-INFM SENSOR Lab, Via Valotti, 9, BRESCIA 25133, Italy O. Sakho Departement de Physique, Universite Cheikh Anta, DIOP, Dakar, BP 5005, Senegal 123 J Nanopart Res DOI 10.1007/s11051-009-9843-3