Resistance transients in thin-film noise data [IC interconnects]

Noise measurements taken under accelerated stressing conditions do not work for the prediction of VLSI interconnect lifetime. This is because a crucial feature of the resistance changes under accelerated bias, which could provide insight into metallization reliability, is obscured by spectral analysis. Distinctive resistance transients occur sporadically during accelerated life testing and it is the presence of these transients that make Fourier analysis inappropriate. Recent work has shown that abrupt changes of resistance (ACRs) in a DC biased thin metal film can be correlated with voiding processes. It is the sensitivity of a measurement system designed to detect very low level noise fluctuations that allows one to detect these small resistance changes. The analysis of this data from a time-domain perspective has great potential for advancing the understanding of damage processes in metallization. This presentation provides details of the detection of resistance transients, evidence of their correlation to voiding processes, and data from a detection system designed to monitor the transients.