Effect of deposition conditions on the structure, phase composition and electrical properties of the chromium silicide films

Thin chromium silicide films with thickness up to 20 nm were deposited by flash evaporation of CrSi2 powder onto silica glass and (100) KCl substrates at temperatures from 20 to 550°C and analyzed by electrical resistance measurements and transmission electron microscopy. The film phase composition depends crucially on deposition procedure: if a CrSi2 powder was thermally treated just prior deposition, CrSi2 film grows otherwise Cr3Si film is formed. Under deposition onto unheated substrate an amorphous film grows. A crystalline phase appears at ~280°C for CrSi2 and 250°C for Cr3Si and furtheron its fraction increases. The CrSi2 film consists of densely packed crystallites, whereas Cr3Si film structure resembles a network of fine crystallites imbedded into amorphous silicon-based matrix. The resistivity of CrSi2 film grows with substrate temperature, whereas that of Cr3Si film reduces. The observed resistivity - film thickness dependence is well described by the Fuchs-Sondheimer model for CrSi2 films and Mayadas-Shatzkes model for Cr3Si films, since in the formers the crystallites size is larger than a film thickness, whereas in the latter's it is less than a film thickness.