A novel diagnostic test generation methodology and its application in production failure isolation

Faster failure isolation is critical for manufacturing yield ramp and product time to market. Higher diagnosis resolution is essential for faster defect isolation and root-cause identification. A detection oriented test set is targeted for fault coverage and does not provide maximum diagnostic resolution. In this paper, we present the design and architecture of a state of the art diagnostic ATPG tool for industrial-scale designs. We develop a novel diagnostic test generation methodology which first generates deterministic diagnostic test content to distinguish the diagnosis suspects. If tester memory is available then additional N-detect oriented tests are generated to augment the content. Further, we present techniques to improve performance of diagnostic fault simulation for industrial-scale designs. Experimental results on Intel® Core™ microprocessor designs indicate 3X-114X speed up with up-to 2X memory overhead. Silicon failure data collected on sort wafer fails showed the effectiveness of the hybrid diagnostic content in improving the diagnostic resolution by 2.8x to 3X when compared with content generated from an industry standard diagnostic test generator. Silicon results are evaluated on Intel® Core™ microprocessor.