Effect of a Thin Cr Layer on the Microstructures and Fracture Behaviours of Copper Films

An investigation on Cu/Cr/Si composite thin films demonstrated that a thin Cr layer affects the microstructures and mechanical behavior of Cu films significantly. The fracture modes changes from brittle fracture to ductile rupture, as indicated by the dimpled rupture of Cu films. Moreover, the Cr sticking layer can result in carrot-shaped rods and a fine grain size. Further analysis indicates their deformation and fracture processes are closely related to the coupling of dislocation-mediated plasticity as well as the formation and growth of voids which act as sites for nucleation of the dimples.