Electromigration failure in Al-Si-1% thin film

The electromigration failure mechanism of sputtered deposited Al-Si-1% meta l films was studied using an integrated circuit device designed according t o CMOS technology. The tests were conducted employing current densities in the range of 1.0-2.0 x 10(6) A/cm(2) and temperatures of 100-200 degrees C. The failure mechanism showed a lognormal distribution and an activation en ergy of 0.54 +/- 0.15 eV was obtained. SEM analysis showed void regions and material depletion, which were responsible for the current flow interrupti on. An exponential reduction of the median-time-to-failure (T-50) was obser ved with the increasing of the metal strip temperature. We found an inverse dependence of T-50 and current density on the power of 'n', which presente d an average value of 1.1. Samples of the Al-Si-1% film submitted to XRD an alysis showed a preferred orientation on the [111] direction, compared to t he [200], indicating a columnar texture of the film.