Built-in Self-Test for Inter-Layer Vias in Monolithic 3D ICs

Monolithic 3D integration provides massive vertical integration through the use of nanoscale inter-layer vias (ILVs). However, high integration density and aggressive scaling of the inter-layer dielectric make ILVs especially prone to defects. We present a low-cost built-in self-test (BIST) method to detect opens, stuck-at faults (SAFs), and bridging faults (shorts) in ILVs. Two test patterns-all-1s and all-0s-are applied to the input side of a set of ILVs (e.g., making up a bus between two tiers). On the adjacent tier (the output side of the ILVs), the test responses are compacted to a 2-bit signature through space compaction. We prove that this compaction solution does not introduce any fault aliasing. Simulations results using HSPICE and M3D benchmark designs show that the proposed BIST method requires low area overhead and test time, but provides effective fault localization and the detectability of a wide range of resistive faults.