Layers of NbSi2 and MoSi2 were grown by means of the implantation of germanium and arsenic ions through films of the respective metals, previously deposited on single crystal silicon substrates. The doses used varied from 1 to 15×1015 ions/cm2 with energies of 150, 200, and 250 keV. The thickness of the silicide layers increases in proportion to the square root of the implanted doses. This observation and other evidence indicate that the process is dominated by the atomic mechanisms encountered in radiation-enhanced diffusion, whereas ballistic mixing effects remain unimportant. The growth of disilicide layers during implantation is discussed with respect to (1) what is known about the growth of these disilicide layers during simple annealing, and (2) what is anticipated for diffusion-controlled solid state processes.