A UNIFIED NEGATIVE-BINOMIAL DISTRIBUTION FOR YIELD ANALYSIS OF DEFECT-TOLERANT CIRCUITS

It has recently been recognized that the yield of fault-tolerant VLSI circuits depends on the size of the fault clusters. Consequently, mode ls for yield analysis have been proposed for ''large-area clustering'' and ''small-area clustering,'' based on the two-parameter negative-bi nomial distribution. We propose the addition of a new parameter, the b lock size, to the two existing parameters of the fault distribution. T his new parameter allows us to unify the existing models and at the sa me time add a whole range of ''medium-size clustering'' models. Thus, we increase the flexibility in choosing the appropriate yield model. W e present methods for estimating the newly defined block size and vali date our approach through simulation and empirical data.