ON STRESS EVOLUTION AND INTERACTION DURING ELECTROMIGRATION IN NEAR BAMBOO STRUCTURE LINES

Electromigration-induced stress in near bamboo structure interconnects has been simulated by the finite element method. The maximum stress a t the juncture of polygranular clusters and bamboo segments increases when the stress profile interacts with the line end. The maximum stres s at final steady state depends on the relative location of the polygr anular cluster in the line under the constant source boundary conditio n. Under the blocking boundary condition, the steady state stress prof ile (if it exists) is determined only by current density and total lin e length and is independent of the microstructure of the line. Finally , the ratio of effective diffusivity of the cluster to that of bamboo segments affects the magnitude of maximum stress at quasi-steady state . (C) 1997 American Institute of Physics.