This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
Investigation of the activation energy (Ea) of electromigration (EM) is one of the effective ways to understand the EM diffusion mechanism  because each diffusion mechanism has its own value.
For instance, an activation energy (Ea) of ~ 0.9 eV is obtained for the Cu width range of 0.1–6 µm when the dielectric diffusion barrier is SiCxNy. 
In this case, the interface between Cu and SiCxNy is the dominant diffusion path for the Cu damascene interconnects regardless of the Cu microstructure (either bamboolike or polycrystalline structures). Note that the Ea of grain-boundary diffusion of electroplated Cu is 1.08 eV. 
 D. Gan, P. S. Ho, R. Huang, J. Leu, J. Maiz, and T. Scherban, J. Appl.
Phys. 97, 103531 (2005).
 T. Usui, H. Nasu, T. Watanabe, H. Shibata, T. Oki, and M. Hatano, Electromigration diffusion mechanism of electroplated copper and cold/hot two-step sputter-deposited aluminum-0.5-wt% copper damascene interconnects, Journal of Applied Physics 98, 063509 (2005).