Electromigration and low-frequency resistance fluctuations in aluminum thin-film interconnections

Low-frequency noise spectra originating from resistance fluctuations in Al films during electromigration were measured in the absolute temperature and current density intervals327 ≤ T ≤ 396K and1.34 × 10⁶ ≤ j ≤ 2.22 × 10⁶A/cm2. The values of SR, the resistance power spectral density, at 20 × 10-3Hz allowed the construction of an Arrhenius plot from which a grain-boundary activation energy value of about 0.6 eV was deduced. This value lies in the range of values found by other authors using different techniques. A first attempt to model the observed dependence of SRonjandTis also described.