<p>A dual damascene process for forming conductive interconnects on an integrated circuit die. The process comprises providing a layer (16) of porous, ultra low-k (ULK) dielectric material in which a via opening (30) is subsequently formed. A thermally degradable polymeric ("porogen") material (42) is applied to the side walls of the opening (30) such that the porogen material penetrates deeply into the porous ULK dielectric material (thereby sealing the pores and increasing the density thereof). Once a conductive material (36) has been provided with the opening (30) and polished back by means of chemical mechanical polishing (CMP), the complete structure is subjected to a curing step to cause the porogen material (44) with the ULK dielectric layer (16) to decompose and evaporate, thereby restoring the porosity (and low-k value) of the dielectric layer (16).</p>
