Post-Bond TSV Defect Detection Circuit Based on a Cross-Coupled Transistor Pair With Positive Feedback Mechanism

In post-bond through-silicon vias (TSVs), existing detection techniques suffer from insufficient defect type coverage, limited detection accuracy, and high sensitivity to process-voltage-temperature (PVT) variations. To address these limitations, this paper proposes a post-bond TSV detection circuit based on a cross-coupled transistor pair with a positive feedback mechanism. The proposed circuit sequentially detects bridge, open, void, and leakage defects by reconfiguring a transmission-gate switch array and a resistor network, utilizing the exponential gain of positive feedback to enable precise discrimination of minute resistance variations. The symmetric topology ensures stability, even under device mismatches and PVT fluctuations. Worst-case PVT corner simulations and Monte Carlo simulations demonstrate that the circuit can reliably detect void defects down to 10 Ω and leakage defects of 4 KΩ within microsecond-scale test durations, with statistical analysis confirming robust performance against process variations. Compared to conventional methods, the proposed design achieves better defect-type coverage, finer discrimination of defect degree, and enhanced immunity to process variations. These results demonstrate the potential of the proposed circuit to improve yield and reliability in 3-D integrated circuits employing TSVs.