Stress- and Electromigration-Induced Voiding and Its Correlation to Macroscopic Stress Changes

Abstract

AbstractThis paper reviews experimental data on stress- and electromigration (EM)-induced voiding in passivated Al- and AlSiCu-lines under different experimental conditions (thermal cycling, iso-thermal annealing without and with EM-current). The data are deduced from measured changes of average metal strain or stress and from in-situ observations in a transmission electron microscope. There are excellent correlations between corresponding data sets showing stress induced voiding during cycling and isothermal annealing without EM-current, but nearly no changes in stresses or void volume during EM-testing. The implications of these results on EM-modelling are discussed.