Correlation between electromigration damage kinetics and microstructure in Cu interconnects

Abstract

Strong correlation of the modes of electromigration damage and microstructure is reported for Cu lms It is found that changes in the microstructure may lead to qualitative variation in electromigra tion damage kinetics from the traditional open circuit due to void growth to continuous damage not leading to failure Surface di usion acting simultaneously with grain boundary mass transport is shown to be critical for damage formation Activation energy of electromigra tion mass transport was measured using a modi ed electrical resistance method and it was determined to be eV indicating grain bound ary di usion