A method of fabricating a thin film from a substrate includes implantation into the substrate, for example made of silicon, of ions of a non-gaseous species, for example gallium, the implantation conditions and this species being chosen, according to the material of the substrate, so as to allow the formation of precipitates confined in a certain depth, distributed within a layer, these precipitates being made of a solid phase having a melting point below that of the substrate. The method optionally further including intimate contacting of this face of the substrate with a stiffener, and detachment of a thin film by fracturing the substrate at the layer of precipitates by applying a mechanical and/or chemical detachment stress under conditions in which the precipitates are in the liquid phase.