Resistance transients in Al-based thin films and activation energy measurements

In this work, we present a study of resistance transients (pulses) observed during noise measurements in Al-based thin films at high current densities and/or high temperatures. It was found that the maximum pulse height M gradually increases with film current density until it reaches a peak at a critical film temperature, T_c. Above the critical temperature, M decreases to a value close to its initial value then increases with the film current density. It was also found that the critical temperature is 254°C for the Al-Si(0.75%)-Cu(0.5%) samples used in this study. In addition, it was found that the number of pulses detected per measurement period increases with increasing film current density. A new technique for determining the electromigration activation energy from the Arrhenius plot of M versus film temperature is also presented. The activation energy values determined using this new technique were between 0.58 and 0.77 eV for the Al-Si(0.75%)-Cu(0.5%) samples