Chemical Vapor Deposition of TiSi Nanowires on C54 TiSi2 Thin Film:An Amorphous Titanium Silicide Interlayer Assisted Nanowire Growth

摘要

A C54-TiSi2 film was grown on a Si substrate at 1073 K by low pressure chemical vapor deposition (LPCVD) employing titanium subchlorides TiCl_(x(g)), generated by reacting between TiCl_(4(g)) and Ti_(s) at 1173 K, as the Ti source. Growth of titanium silicide (TiSi) nanowires (NWs; diameter 30-80 nm, length several micrometers) on a C54-TiSi2 film was observed. Growth direction of the NWs was determined to be along the [010] axis. An amorphous titanium silicide interlayer was observed between the NWs and the C54-TiSi2 film. This interlayer, probably existing as a quasi-liquid thin film during the growth, appears to be the key factor to assist the NW development. Field emission properties, turn-on field E_o and field enhancement factor β, of the vertically grown TiSi NWs were determined to be 5.25 V μm~(-1) and 876, respectively.