Patent ID: 7380225

Claim:
A computer-performed method for efficiently analyzing a failure rate of a cell in an array of cells, comprising: identifying a failure region of interest corresponding to values of circuit parameters of said cell from a result of a statistical performance analysis, wherein the failure region of interest is determined according to first samples of a performance variable; selecting a sampling function center in conformity with a position of said failure region of interest to increase a frequency of samples of said performance variable in or near said region of interest; performing a mixture importance analysis within a computer system in conformity with said sampling function center to determine effects of variation of said cell circuit parameters within and near said failure region of interest on said failure rate, wherein the mixture importance analysis computes second samples from a mixture distribution obtained by summing multiple differing distributions of said performance variable according to weighting coefficients associated with each of said multiple distributions, whereby said second samples are generated according to a mixture of said multiple distributions; and storing a result of said mixture importance analysis within a memory of said computer system.