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 intervals 327 \leq T \leq 396 K and 1.34 \times 10^{6} \leq j \leq 2.22 \times 10^{6} A/cm 2 . The values of S R , the resistance power spectral density, at 20 × 10 -3 Hz 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 S R on j and T is also described.