We have studied morphological changes of an interface in a strong electric field which is normal to the initially planar interface. Electromigration along the interface in a two phase metallic systemA‐Bof the immiscible components has been considered. The stresses arising during electromigration of the components were taken into account. A nonlinear equation has been derived for the interface evolution in the electric field, allowing for curvature of the interface. It was shown that the interface diffusion in an electric field leads to the formation of a periodic corrugation on the interface if the components are distinguished by their electric charges. The corrugation increases with time and is transformed into a channel‐hillock‐like structure. The nonlinear equation was analyzed numerically for the steady‐state case. The shape and the growth rate of hillocks on the interface have been calculated. ©1995 American Institute of Physics.