The statistical distribution of 1/f/sup 2/ noise in thin metal films under accelerated electromigration test conditions

The levels of excess current noise in metal thin films under accelerated stress conditions have been shown to correlate well with traditional electromigration lifetimes determined from median time to failure (MTF) tests. The goals of this study were to obtain the magnitudes of a series of noise measurements taken on a metal-thin-film stripe or a set of metal-thin-film stripes where the activation energies for the noise generation processes could be assumed to be normally distributed. The values obtained from the noise measurements were determined, and the statistical distribution of the reciprocals of these values was examined. In particular, an attempt was made to determine the goodness' of fit between the 1f//sup 2/ noise measurement data and the theoretical lognormal distribution. It is shown that the reciprocal of the 1/f/sup 2/ noise magnitudes, taken at a single frequency, for a large group of identical films can also be modeled by the lognormal distribution.<>