The Nature of Nanometer Timing Failures

摘要

Timing failures are not catastrophic but show a clock frequency capability that is less than the product specification. There may be windows of pass or fail, and timing failures can occur in an IC with or without the presence of defects. A simple example of intrinsic IC failure occurs when the clock frequency is turned up on a perfectly good IC-all ICs will fail at some maximum operating clock frequency. Why? There are several reasons, and all of them ultimately violate design timing rules. Statistical variation within the IC can cause defect-free failure at frequencies below the product specification. It is the statistical interaction of random parameter values from the manufacturing process that can cause intrinsic frequency failure. Extrinsic timing failures are those with defects in the signal path. Resistive vias are a good example of one source of extrinsic timing failures.