Abstract: The method of the present invention is related to the fabrication of a copper-based multilevel interconnect structure. This copper-based multilevel interconnect structure is based on the formation of vertical metal connections through copper-containing metal stud growth on an underlying horizontal metal pattern, followed by a stud encapsulation step against copper diffusion into the surrounding dielectric, i.e. the insulating layers. This method is of particular interest when the insulating layers used to obtain this interconnect structure are polymer layers with a low dielectric constant and preferably with a high degree of planarization.