Current density dependence of electromigration t/sub 50/ enhancement due to pulsed operation

Abstract

Two effects that complicate the electromigration characterization of metallization for pulsed stress are discussed. One is the dependence of the t/sub 50/ enhancement (due to pulsed operation) on current density, and the other is a decrease of this enhancement over a range of frequencies (0.2 to 2 MHz) that is connected with the Joule heating. These effects are discussed in terms of changes in the buildup and relaxation response times of the excess vacancy concentrations.<>