Statistical threshold formulation for dynamic Idd test

Process variations degrade the resolution and consequently the fault coverage of I_dd test techniques. We develop statistical techniques to set thresholds in a dynamic I_dd test process. The techniques use principal component analysis to identify process corners and compute statistical models. Our techniques are applied to average current-based dynamic test and to test based on the energy consumption ratio. We demonstrate that our techniques lead to computationally efficient methods to set accurate thresholds without either significant yield or fault coverage loss. To the best of our knowledge, this is the first systematic technique to set thresholds for a dynamic I_dd test method