Growth kinetics Of CU6Sn5 and Cu3Sn compounds in Cu/Sn thin film couples was studied by in situ resistivity measurements and X-ray diffraction analysis. The Cu6Sn5 and Cu3Sn intermetallic compounds were found to form in sequence when the Cu/Sn bimetallic samples were isochronally annealed from room temperature to 220 degrees C. A kinetic model was presented to explain sequential appearance of the Cu6Sn5 phase and the Cu3Sn phase during the isochronal annealing process. The activation energies of Cu6Sn5 and Cu3Sn compound growth in Cu/Sn thin film couples were determined from the in situ resistivity measurements to be 0.87 eV and 1.05 eV, respectively. (c) 2006 Elsevier B.V. All rights reserved.