There is described a process for the formation on a substrate of a refractory metal silicide layer, usable particularly for producing the interconnection layers of integrated circuits. This process consists of successively depositing on the substrate a first amorphous hydrogenated silicon layer, a second amorphous hydrogenated refractory metal layer, e.g. of tungsten, titanium, molybdenum or tantalum, and a third amorphous hydrogenated silicon layer. The thus coated substrate is then subjected to an annealing treatment at a temperature equal to or higher than 350.degree. C. in a hydrogen atmosphere. Preferably, following the deposition of the three layers, the coated substrate undergoes ionic implantation, e.g. using tungsten ions, for producing defects in the layers, which makes it possible to speed up the formation of the refractory metal silicide layer during the annealing stage.