On Accuracy of Switch-Level Modeling of Bridging Faults in Complex Gates

Bridging faults have been shown to be a major failure mode in VLSI devices. This study examines nMOS and CMOS complex gates in detail for bridging faults. Analysis is carried out using both switch and circuit level models for comparison. It is shown that in most cases, the switch level analysis predicts the correct behavior. A set of conditions are presented, under which the switch level analysis may fail to predict the correct behavior. These conditions can be used for accurate switch level test generation and simulation.