It has been shown that enhanced electric field intensity (0-4.0 kV/cm) has an obvious effect on accelerating atom diffusion in Cu/Ta/Si interconnect stacks at 650 degrees C. The theoretical deduction proves that diffusion coefficient is accelerated proportional to an acceleration factor (1+a.alpha(E/0.8))(2). The analysis indicates that the accelerating effect is mainly attributed to the perturbation of the electric state of the defects and enhanced vacancy and dislocation densities. (C) 2016 Elsevier B.V. All rights reserved.