Solid-State Formation of Intermetallic Compounds in Co-Sb Couple Nanowires

Nanointerconnection technologies have attracted much attention for the future electrical interconnection in electronic packaging. Nanowire interconnection needs to form the intermetallic compounds (IMCs) between the nanowires, in order to effectively reduce the contact resistances. In this study, the couple nanowires of Co and Sb elements were selected to investigate the IMC formation in one dimensional confinement. The Co and Sb nanowires were electrochemically deposited into the anodic aluminum oxide templates, in sequence, which had the pore diameters of about 30 and 60 nm, respectively. Results show that the CoSb phase is formed between Co nanowire and Sb nanowire after heat-treatment at 773 K. The IMC formation was ascribed to the dominant diffusion of Sb atoms toward the Co nanowire. The fast diffusion of Sb atoms toward the Co nanowire resulted in the formation of Kirkendall voids between the IMC and Sb nanowires.