Alternative Architectures Toward Reliable Memristive Crossbar Memories

Resistive random access memory (ReRAM), referred to as memristor, is an emerging memory technology to potentially replace conventional memories, which will soon be facing serious design challenges related to continued scaling. Memristor-based crossbar architecture has been shown to be the best implementation for ReRAM. However, it faces a major challenge related to the sneak current (current sneak paths) flowing through unselected memory cells, which significantly reduces the voltage read margins. In this paper, five alternative architectures (topologies) are applied to minimize the impact of sneak current; the architectures are based on the introduction of insulating junctions within the crossbar. Simulations that were performed while considering different memory accessing aspects, such as bit reading versus word reading, stored data background distribution, crossbar dimensions, etc., showed that read margins can be increased significantly (up to 4×) as compared with standard crossbar architectures. In addition, the proposed architectures eliminate the requirement for extra select devices at each cross point and have no operational complexity overhead.