Exploiting Double-Barrier MTJs for Energy-Efficient Nanoscaled STT-MRAMs

This paper explores performance and technology-scalability of STT-MRAMs exploiting double-barrier MTJs (DMTJs) as comparatively evaluated with respect to conventional solution based on single-barrier MTJs (SMTJs). The comparative study was carried out at different design abstraction levels: (i) a bitcell-Ievel analysis relying on the use of Verilog-A compact models, and (ii) an architecture-level analysis for various memory sizes. Overall, our simulation results point out that, thanks to the reduced switching currents, DMTJ-based STT-MRAMs allow reducing write latency of about 60% than their SMTJ-based counterparts. This is achieved while assuring lower energy consumption under both write (-40%) and read (-27%) accesses, at the cost of reduced sensing margins.