Fabricationof Al microspheres by electromigration using a metal line with a sudden change in geometrical shape

A technique using the sudden change in the geometrical shape of an Al line is introduced for the effective accumulation of atoms and,therefore, the fabrication ofmicro materials by electromigration. The effectiveness of the present technique is verified by the formation of an Al microspherefrom a predefinedhole.According to a finite element analysis of this electrical-thermal problem, the physical mechanismgoverning the observed behaviorcan be attributed to a decrease in atomic fluxalong the electron flow direction, resulting from asudden change in geometry,in the small region surrounding the predefined hole.