High-resolution in-situ of gold electromigration: test time reduction

Electromigration Reliability of Passivated Gold Interconnects for GaAs Devices

“…The maximum Joule-heated Au film temperature was 12°C above the oven temperature for the highest current density of 2 MA/cm 2 . This stress current density and induced Joule heating on these Au interconnect structures was significantly lower than previous studies [5,6], thus avoiding large thermal gradients and potentially erroneous failure mechanisms that cause inaccuracy in electromigration model parameter extraction.…”

“…An activation energy of 0.80 ± 0.05 eV for electromigration in these Au interconnects was extracted with 95% confidence intervals. This activation energy is near the middle of reported values (0.68 eV and 1.0 eV) for resistometric method studies [5,6]. These studies unfortunately applied current densities above 3 MA/cm 2 where accounting for Joule heating is difficult and can lead to inaccuracies in extraction of activation energy.…”

“…In addition to the vital role of Au metallization on GaAs devices for ohmic contacts, Au interconnects are expected to have improved electromigration reliability due to its higher melting point. However, published investigations on electromigration reliability of passivated electroplated Au interconnects are both scarce and inadequate [5,6]. Thus, the objective of this study was to accurately measure electromigration model parameters for passivated Au interconnects utilizing moderately accelerated and precisely controlled stress conditions applied on a statistically significant sample.…”

Electrical Failure Analysis of Au Nanowires

“…The current exponent n was found to lie commonly between 1 and 3 (as mentioned in [17]). Croes et al [4] studied electromigration in gold interconnects of width 3 µm, thickness 1.4 µm, and length 800 µm, and used a plane to fit through the experimental data and found that n = 2.00 ± 0.51 with 95% confidence. Therefore, we used n = 2 in our calculation.…”

“…However, the activation energy of the Au nanowires, which is an important parameter to characterize the reliability of a material, was not determined. Croes et al [4] have studied the electromigration behavior of Au interconnects of micrometer size, and an activation energy E a = 0.675 eV was found. To our knowledge, the activation energy of Au nanowires with the sub-100 nm thicknesses and widths has not been widely reported.…”