Self-assembly of TiSi nanowires on TiSi2 thin films by APCVD

Titanium silicide thin films and nanowires (NWs) were prepared on a glass substrate using the APCVD method. Gaseous SiH4 and TiCl4 were used as precursors for Si and Ti, respectively. TiSi2 thin films were precipitated on the glass substrate first, and then single-crystal TiSi NWs were grown on the TiSi2 thin films as-prepared by controlling the concentrations of the source gases, SiH4 and TiCl4, without using any catalysts. The TiSi NWs were typically 1–2 μm long and 15–50 nm thick. The growth direction of the NWs was perpendicular to the (1 1 0) plane, in which a competition in growth rate among different crystallographic planes of the TiSi crystalline phase occurs. The oriented growth of the TiSi crystalline phases is responsible for the formation of the NWs.

► TiSi nanowires are formed on TiSi2 thin films on glass substrate by APCVD with gaseous SiH4 and TiCl4 as precursors of Si and Ti, respectively.
► TiSi nanowires are formed via the induction of TiSi2 thin films without using any catalysts.
► The mechanisms for formation of the TiSi2 thin films and the TiSi nanowires are revealed.