A method of manufacturing metallic interconnects for an integrated circuit includes forming an interconnect layout including at least one line including a non-diffusing material, forming a diffusing barrier layer on the line, forming an opening extending completely through the diffusing barrier layer and exposing a portion of the line, depositing a diffusing layer on the diffusing barrier layer such that a portion of the diffusing layer contacts the portion of the line, and thermally reacting the diffusing layer to form the metallic interconnects. Thermally reacting the diffusing layer chemically diffuses a material of the diffusing layer into the at least one line and causes at least one crystalline grain to grow along a length of the at least one line from at least one nucleation site defined at an interface between the portions of the diffusing layer and the line.