Sequential silicide formation between vanadium and amorphous silicon thin-film bilayers

Solid-state reactions between bilayer thin films of vanadium and amorphous silicon with an excess amount of vanadium have been studied by Rutherford backscattering spectroscopy and Seemann-Bohlin x-ray diffraction. In prior studies of the interaction between vanadium thin films and single-crystal silicon, VSi2 has been the only compound observed. In the present study a sequence of compounds was observed. The first silicide, VSi2, was observed to form at 475 °C. At higher temperatures the compounds V 5Si3 and V3Si formed in sequence. The growth of VSi2 is linear in time with an activation energy of 2.3±0.4 eV. The growth of V5Si3 is also linear with an activation energy of 2.5±0.1 eV.