Activation Energy Estimation Using Cox's Distribution-Free Method.

It is shown that the activation energies for failure rate calculations can be conveniently estimated using Cox's method --- a distribution- free method widely applied in the medical field. We report the first application of this method to thin oxide reliability analysis. Using published oxide breakdown data, we found that the activation energies determined by Cox's method are lower than those determined by the standard method. Our results suggest that the activation energies used in some DRAM failure rate calculations may be higher than the correct values by an order of magnitude.