ELECTROMIGRATION IN 2-LEVEL BAMBOO GRAIN-STRUCTURE AL(CU) W INTERCONNECTIONS/

Electromigration in two-level Ti/Al(0.5%Cu)/Ti lines with interlevel W stud interconnects has been investigated using both drift velocity an d resistance techniques. It is shown that the mass depletion from the cathode end correlates with resistance change and electromigration fai lure in line/stud chains. The mean time to failure was found to be wea kly dependent on linewidth from 1.9 mum (two grains across any linewid th) to 0.7 mum (bamboo structure). The dominant mass transport path is along the edges of the metal line.