Quiescent-Signal Analysis: A Multiple Supply Pad IDDQ Method

Increasing leakage current makes single-threshold IDDQ testing ineffective for differentiating defective and defect-free chips. Quiescent-signal analysis is a new detection and diagnosis technique that uses IDDQ measurements at multiple chip supply ports, reducing the leakage component in each measurement and significantly improving detection of subtle defects. The authors apply regression and ellipse analysis to data collected from 12 test chips to evaluate the technique.