TACHI: Tests as a Chip Identifier

This paper proposes a novel method for establishing individual chip traceability in shipped integrated circuits without requiring additional circuit area. The proposed approach leverages inherent characteristic variations present among chips by storing pre-shipment test measurements to enable accurate chip identification. These results are processed to generate criterion vectors that enable accurate chip identification. Evaluation using real wafer test data containing 21,974 chips demonstrated a 99.32% identification accuracy when utilizing criterion vectors constructed from 80 different test items.