Architecture design exploration of three-dimensional (3D) integrated DRAM

Motivated by increasingly promising threedimensional (3D) integration technologies, this paper reports an architecture design of 3D integrated dynamic RAM (DRAM). To accommodate the potentially significant pitch mismatch between DRAM word-line/bit-line and through silicon vias (TSVs) for 3D integration, this paper presents two modestly different coarse-grained inter-sub-array 3D DRAM architecture partitioning strategies. Furthermore, to mitigate the potential yield loss induced by 3D integration, we propose an interdie inter-sub-array redundancy repair approach to improve the memory repair success rate. For the purpose of evaluation, we modified CACTI 5 to support the proposed coarse-grained 3D partitioning strategies. Estimation results show that, for the realization of a 1Gb DRAM with 8 banks and 256-bit data I/O, such 3D DRAM design strategies can effectively reduce the silicon area, access latency, and energy consumption compared with 3D packaging with wire bonding and conventional 2D design. We further developed a memory redundancy repair simulator to demonstrate the effectiveness of proposed inter-die inter-subarray redundancy repair approach.