Architecture of Ring-Based Redundant TSV for Clustered Faults

Three-dimensional integrated circuits (3-D-ICs) that employ the through-silicon vias (TSVs) vertically stacking multiple dies provide many benefits, such as high density, high bandwidth, and low power. However, the fabrication and bonding of TSVs may fail because of many factors, such as the winding level of the thinned wafers, the surface roughness and cleanness of silicon dies, and bonding technology. To improve the yield of 3-D-ICs, many redundant TSV (RTSV) architectures were proposed to repair 3-D-ICs with faulty TSVs. These methods reroute the signals of faulty TSVs to other regular TSV or RTSV. In practice, the faulty TSVs may cluster because of imperfect bonding technology. To resolve the problem of clustered TSV faults, router-based RTSV architecture was the first proposed to pay attention to it. Their method enables faulty TSVs to be repaired by RTSVs that are farther apart. However, to repair some rarely occurring defective patterns, their method requires too much area. In this paper, we propose a ring-based RTSV architecture to utilize the area more efficiently as well as to maintain high yield. Assume that the size of the TSVs is 1 mu m. Simulation results show that for a given number of TSVs (8x8) and TSV failure rate (1%), our design achieves 58.9% area reduction of MUXes per signal, 54.6% total area reduction per signal, and 50.54% total wire length reduction while the yield of our ring-based RTSV architectures can still maintain 98.47%-99% as compared with the router-based design. Furthermore, the shifting length of our ring-based RTSV architecture is at most 1, which guarantees at most one MUX-delay timing overhead of each signal.