Microscopic Measurements of Electromigration Damage Using Electrical Measurements

Abstract

AbstractContinuous measurements have been made of the changes in several electrical quantities of Al 4%Cu tracks during the lifetime under electromigration stress. The changes in resistance, second harmonic and the second harmonic delay have been used to determine the changes in the track cross-section, resistivity and temperature. During most of the lifetime the results are consistent with a linear increase in the microscopic damage occurring uniformly throughout the track. During the final phase of the life there is evidence of large void formation with subsequent healing. Considerable information can be obtained about these processes and the extent to which they are reversible. The observed events are compared with the changes which have been predicted by specific mechanisms.