Structural investigations of the C49-C54 transformation in TiSi2 thin films

A detailed analysis of the microstructure of TiSi2 thin films has been performed by X-ray diffraction, transmission electron microscopy (TEM) and Raman spectroscopy. Samples were obtained by rapid thermal annealing or by annealing under vacuum in a high-temperature diffraction stage. C49 films obtained by rapid annealing give broadened X-ray diffraction profiles that cannot be explained by using simple grain-size considerations. The diffraction profiles recorded from C54 films are close to powder patterns. Long annealing gives films where grain-size is close to film thickness. Some 022 texturing is present in C54 films, Raman spectra do not depend on the annealing type. In the C49 series, as film thickness increases, a line-shift towards higher wavenumber is detected. In thinner C54 films, a polarization effect suggesting a possible in-plane preferred orientation has been observed.