Circuit structure fabrication methods are provided which include: patterning at least one opening within a dielectric layer disposed over a substrate structure; providing a liner material within the at least one opening of the dielectric layer; disposing a surfactant over at least a portion of the liner material; and depositing, using an electroless process, a conductive material over the liner material to form a conductive structure, and the disposed surfactant inhibits formation of a void within the conductive structure.