AC coupled interconnect for dense 3-D ICs

This paper presents the potential application of AC coupled interconnect (ACCI) for dense three-dimensional (3-D) integrated circuits (ICs). The concept of inductive ACCI for 3-D ICs has been proposed. Combined with the "through vias" technology, inductive ACCI can provide small pitch vertical interconnects, as well as an excellent thermal solution for dense 3-D ICs. Transformer modeling and transceiver circuit design have also been investigated. Simulations predict that, for 20 μm thinned die stacks coupled by a 100 μm diameter transformer, the transceiver circuit fed with a 5 Gbps data stream consumes 14.5 mW power.