Hazard-function implications of stochastic-deterioration and distributed-defect concentrations

Two candidate models of the relationship between the initial defect concentration in a population of integrated circuit (IC) devices and the associated life distribution are presented. One of the models is based specifically upon wafer geometry while the other portrays stochastic deterioration as the the accumulation of degradation reaction product. The two models are subjected to computer simulation in order to determine if either displays behavior that is consistent with empirical experience. Unfortunately, while both models display some reasonable behavior, neither may be said to provide an adequate general description of IC failure dependence upon initial defects