Formation of the TiSi(2)C40 as an intermediate phase during the reaction of the Si/Ta/Ti system

The effect of a thin Ta layer at the Si/Ti interface on the intermediate phase formation has been studied in detail by in situ sheet resistance, x-ray diffraction, transmission electron microscopy and Rutherford backscattering spectroscopy of partially reacted samples. When a Ta layer is deposited at the Si/Ti interface, a new intermediate phase has been detected, i.e. the hexagonal TiSi2 C40. This phase grows on the C40-TaSi2 that is formed at the interface with silicon. The lattice parameters of the C40-TiSi2 obtained by ab initio calculations agree quite well with the experimental ones.