Metallic deposits can be produced on the surface of silicon crystals by immersion in aqueous solutions containing fluoride and the metallic ions. This work aims to elucidate the general mechanism of the deposition process, based on "in situ" electrochemical measurements under potentiostatic control and "ex situ" microscopic and spectroscopic techniques. The mechanism developed takes into account the classical concepts of semiconductor electrochemistry, as well as the recent advances in the understanding of silicon chemistry. The consequences of this study and its technological applications are also discussed.