Realizing a high measure of confidence for defect level analysis of random testing

The defect level in circuit testing is the percentage of circuits, such as chips, which are defective and shipped for use after testing. In this work, it is demonstrated that the defect level of testing a circuit using random patterns should have a probability distribution rather than just a single value. Based on this concept, the confidence degree of a specified defect level for random testing is thus guaranteed. Yield value is one of the parameters for defect level analysis, and methods for yield estimation are proposed. The performance of these methods is evaluated using both Monte Carlo simulation and theoretical analyses. Experiments using computer simulation have been conducted for this work, and the results are very encouraging