Reductions in quality caused by uneven fault coverage of different areas of an integrated circuit

摘要

This paper addresses problems associated with the production and interpretation of traditional fault coverage numbers. In particular, the issue of nonuniform distribution of detected faults is addressed, It is shown that when any degree of defect clustering occurs in the IC fabrication process, there is a very big difference in final quality between covering the chip evenly all over and leaving parts relatively untested, even if the coverage is the same in both cases. Empirical evidence is given to support the theory.