Reliable and high performance STT-MRAM architectures based on controllable-polarity devices

摘要

Source degeneration of access devices in the parallel (P)_ anti-parallel (AP) switching in Spin Transfer Torque Magnetic Random Access Memories (STT-MRAM) has ultimately been a limiting factor in the operational speed of these types of memories. In this work, new architectures for memory single-cells and arrays of cells are presented that utilize Schottky-Barrier Silicon Nanowire Field Effect Transistors with polarity control capabilities (e.g., SiNW-FETs), to substantially increase the performance of STT-MRAM, specifically Multi-Level Cell (MLC) STT-MRAM. The proposed design offers built-in reliability improvement as it omits one of the available four states in the MLC STT-MRAM memory facilitating the resistance level detection for peripheral circuitry. Our simulation results of the developed memory cell show 49.7% reductions in P-AP switching time, as well as 51.3% increases in available drive current under 1.4V supply voltage when compared to FinFET 22imi technology. With respect to memory arrays, the proposed architecture demonstrates an average write latency reduction of 37% in comparison with FinFET 22nm technology node.