Statistics of microstructure for via metallization and implication for electromigration reliability

Abstract

Damage formation due to electromigration (EM) in 0.6 /spl mu/m AlCu via/line interconnect structures has been found to be dominated by void formation at grain boundaries near vias. Electron backscatter diffraction (EBSD) was used to analyze the grain structure, and it was found that the orientations of grains near vias show a higher frequency of deviation from (111). The damage formation can be directly correlated to the local grain misorientation. The implication of this result for EM reliability is discussed.