Structure having cavities and process for producing such a structure

Claim 1

A process for producing a structure having a substrate, a thin surface film of a non-conducting material, joined to one face of the substrate, said substrate having cavities flush with said face, the process comprising the following successive steps: etching cavities in one face of a substrate, the cavities having in the plane of the substrate face at least one dimension which is a function of the thickness of the surface film in order to correctly secure the latter; joining a non-conducting material wafer having a solid portion, an intermediate layer and a thin film to the face of the substrate wherein said thin film is adjacent said face of the substrate; thinning the wafer to obtain a thin surface section, the thinning of the wafer being obtained by separating the film of the solid portion from the intermediate layer; wherein the intermediate layer is a layer of microbubbles between the thin film and the solid portion and obtained by prior implantation of gas in the wafer, and the separation of the film is brought about by cleaving the wafer along a cleaving plane defined by the microbubble layer.