The effect of elastic constraint upon electromigration along an isolated interface, embedded in an elastic matrix, was studied. It was found that the steady-state stress distribution was linear along the conducting region of the boundary, but there was an inverse square root singular stress just outside of this region. A stress intensity factor could be defined which, when equated to the fracture toughness of the surrounding material, predicted a critical line length for cracking of the passivation. This critical line length scaled as the inverse two-thirds power of the electric field. It was shown that the distribution of matter along the boundary was not monotonic; even in the steady state. Instead, there were maxima and minima at some distance from both ends. The stress and matter distributions could be combined so as to predict conditions for void nucleation.

M.D.Thouless, H.Yu, Z.Zhao, W.Yang: Journal of the Mechanics and Physics of Solids, 1996, 44[3], 371-87