A fast testing of electromigration immunity using noise measurement technique

A quick wafer-level evaluation technique for electromigration immunity is proposed. Noise measurements (1/f, 1/f/sup 2/) are performed on a test pattern with stress gradients under high current density up to 2*10/sup 7/ A/cm/sup 2/. Each of the measurements is completed within a few minutes. The temperature of the interconnections (200 degrees C for a current density of 2*10/sup 7/ A/cm/sup 2/) is low enough to evaluate electromigration. The effectiveness of the proposed technique has been verified by observing that the current noise spectrum is closely related to the void formation.<
>