RRAM Crossbar Arrays for Storage Class Memory Applications : Throughput and Density Considerations

As more and more high density memories are required to satisfy the Internet of Things ecosystem, academics and industrials are looking for an intermediate solution to fill the gap between DRAM and Flash NAND in the memory hierarchy. The emergence of Resistive Switching Technologies (RRAM) proposes a potential solution to this demand for fast, low cost, high density and non-volatile memory. However, nowadays transistor-less RRAM-based architectures, such as Crosspoint, suffers of several issues such as sneakpath, IRdrop and periphery overhead. In this work, we propose to explore the positioning of RRAM crosspoint memories regarding DRAM and NAND in terms of density and write throughput. We present several design guidelines then show that for the optimal RRAM crosspoint architecture (2-layers with common bitline), massively multiple bank write is the solution to optimize density and write throughput to around 20-100Gbit/cm2 and 200-500MB/s respectively for 32 to 64 parallel access.