Samples consisting of Fe deposited onto a Si wafer covered with its native oxide layer have been studied by photoelectron spectroscopy for different Fe coverages and different deposition techniques involving different kinetic energies for the deposited Fe atoms. We find that the Fe atoms are buried into the substrate even for low kinetic energy techniques, and that a reduction of the Si oxide concomitant with an oxidation of the Fe occurs. This reaction can be assisted by increasing the kinetic energy of the Fe atoms.