Fault Coverage Requirement in Production Testing of

A bstract–A technique is deseribed for evahsating the effectiveness of production tests for large wale integrated (LSI) circuit chips. It is based on a model for the distribution of faults on a chip. The model requires two pammeters, the average number (no) of faults on a faulty chip and the yield (Y) of good chips. It is assumed that the yield either is kmown or can be calculated from the available formulas. The other parameter, no, is determined from an experimental procedure. Once the model is fully characterized, it allows calculation of the field reject rate as a function of the fault coverage. The technique implicitly takes into account such variables as fault simulator characteristics, the feature size, and the manufacturing environment. An actual LSI circuit is used as an example. ~rHE reasons for the practical impossibility of obtaining acomplete functional test for a large scale integrated (LSI) circuit may be found among the following attributes: 1) im