Role of the substrate in the C49-C54 transformation of TiSi2

In this work we report the results of the crystallographic and morphologica l characterization of TiSi2 films grown on a patterned and on a blanket Si substrate. We show that the C49 films grown on crystalline silicon exhibit a rougher surface with respect to that grown on polycrystalline substrate. The different surface morphology is maintained after transformation to the C54 phase. This latter is always (040) textured in the case of patterned fi lms, whereas in blanket films texturing occurs only on a polysilicon substr ate, The C49 phase displays (200) texturing when the film is grown on singl e crystalline Si(100), while random orientation of the grains is detected i n the other cases. The experimental indications are associated with semiemp irical total energy estimations of the surface energies for the two competi ng phases. From this comparison it turns out that, in the case of texturing , the preferential surfaces facing the substrate are the most energetic. (C ) 2000 American Vacuum Society. [S0734-211X(00)02402-1].