On TSV array defect detection method using two ring-oscillators considering signal transitions at adjacent TSVs

In 3D IC testing, resistive open defects in TSVs are difficult to test since its delay size is usually very small. In this paper, we propose a new test circuit for detecting delay faults in TSVs considering the coupling effect between adjacent TSVs in a TSV array since a transition signal at the defective TSV is more affected by crosstalk from its adjacent lines compared with a fault-free TSV. In the proposed design-for-testability circuit, TSVs are connected into two rings that can provide opposite transitions for adjacent TSVs to increase the crosstalk induced delay. We estimated the detectability of open defects in a TSV by simulation.