Functional Failure Analysis by Induced Stimulus

In the field of failure analysis of integrated circuits, diagnosing functional failures is a requirement. Traditional beam-based analysis techniques use a scanning laser or e-beam to induce a parametric shift which is monitored through changes in current or voltage driven to the device. Deep submicron technologies frustrate these analytical methods due to the nearly immeasurable parametric shifts externally caused by a small signal leakage path internally. These internal failures can be identified functionally by timing, temperature or voltage dependencies but the exact location of the fault is difficult to isolate. RIL (Resistive Interconnect Localization) is a newer technique which can identify via anomalies functionally using induced thermal gradients to the metal but does not address how to uniformly inject the thermal energy required in the silicon to analyze timing design deficiencies and other defects. 1 With SIFT (Stimulus Induced Fault Testing), numerous stimuli will be used to identify speed, fault, and parametric differences in silicon. The heart of this technique revolves around intentionally disturbing devices with external stimuli and comparing the test criteria to reference parts or timing/voltage sensitivities. Synchronous interfacing is possible to any tester without any wiring or program changes.