First-principle theoretical study on the dynamical electronic characteristics of electromigration in the bulk, surface and grain boundary

New formula for the driving force of electromigration have been found using new concepts of (1) kinetic energy density, (2) tension density, and (3) effective charge tensor density. The new "dynamic" wind charge tensor density (Z) over left right arrow (a dynamic wind) ((r) over left right arrow) is revealed over and above the conventional "static" wind charge tensor density ((Z) over left right arrow)(a static wind) ((r) over left right arrow). Some numerical analysis will be demonstrated for possible application to electromigration reliability problems of ULSI devices where extremely high current densities should be maintained through ultra thin film interconnects. Key issues in this study are the comparative study of the dynamical electronic characteristics for the electromigrating regions in the bulk, surface, and grain boundary.