Fault localization using time resolved photon emission and stil waveforms

Abstract

Faster defect localization is achieved by combining IC simulations and internal measurements. Time resolved photon emission records photons emitted during commutations (current) rather than determining the voltage states. Comparing measured waveforms with simulations (STIL/VCD) localizes functional faults and timing issues. Summary Software diagnosis makes it possible to investigate many IC defects with fault simulation tools. Internal probing techniques, such as time resolved photon emission (TRP), can access otherwise inaccessible nodes. Hardware diagnosis can fine-tune the defect analyses and validate simulations by contributing actual measurements. The combination of software diagnosis and internal probing can reduce simulation time and internal measurements for faster localization of the defect. The challenge is to determine quickly if a measurement is good or not: Can some signal be measured (the transistor is at least activated)? Are the measured delays matching the simulation? If ATE detects a problem, the method presented in the paper saves time in locating the fault site by applying simulations to determine the duration and location of a meaningful measurement.