A process for fabricating a hydrogenated amorphous silicon carbide film having through-pores includes the formation on a substrate of a film consisting of an amorphous hydrogenated silicon carbide matrix in which silicon oxide nanowires are dispersed therethrough, and then the selective destruction by a chemical agent of the silicon oxide nanowires present in the film formed at step a). Applications include microelectronics and micro-technology, in all fabrication processes that involve the degradation of a sacrificial material by diffusion of a chemical agent through a film permeable to this agent for the production of air gaps, in particular the fabrication of air-gap interconnects for integrated circuits.