Comparison of Wafer-level Spatial IDDQ Estimation Methods: NNR versus NCR
نویسندگان
چکیده
Extending the useful life of IDDQ test to deep submicron technologies has been a topic of interest in recent years. IDDQ test loses its effectiveness as the signal to noise ratio degrades due to rising background current and fault-free IDDQ variance. Defect detection using IDDQ test requires separation of deterministic sources of variation from defective current. Several methods that use deterministic variation in IDDQ at the wafer level for estimating fault-free IDDQ of a chip are proposed. This paper compares two such methods: Nearest Neighbor Residual (NNR) and Neighbor Current Ratio (NCR). These methods are evaluated using industrial test data for a recent technology.
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