Motion of Electron Gas and the Induced Nanofilm Electromigration

Understanding how electron gas moves and induces electromigration is highly desirable in micro- and nano-electronic devices. Based on introducing some novel concepts of electron gas momentum, kinetic energy and resisting force, we establish the continuum, momentum and energy conservation equations of the electron gas in this paper. Through analyzing the control equations, the Ohm’s law can be derived if the inertial force or the kinetic energy of the electron gas is ignored. Thus, the Ohm’s law is no longer applicable if the variation of the electron gas momentum is too large to be ignored. For instance, the kinetic energy variation can not be ignored for the electron gas with a high velocity flowing along the conductor with variable cross-sections. Under such conditions, the electric resistance of the section-variable conductors is a function of the electric current density and direction, which is referred to as a kinetic energy effect on the electric resistance. Based on the control equations of the electron gas motion, the electron wind force and the kinetic energy can also be calculated. The kinetic energy transferred from the electron wind to metallic atoms increases greatly with the increasing electric current density. It may be comparable with the activated energy of the metallic atoms in nanofilms. Thus, the electromigration induced by the electron wind can be regarded as another kind of kinetic energy effect of the electron gas, i.e. kinetic energy effect on the electromigration.