Energy-Efficient Phase-Change Memory with Grapheneas a Thermal Barrier.

Phase-change memory (PCM) is an importantclass of data storage, yet lowering the programming current of individualdevices is known to be a significant challenge. Here we improve theenergy-efficiency of PCM by placing a graphene layer at the interfacebetween the phase-change material, Ge2Sb2Te5(GST), and the bottom electrode (W) heater. Graphene-PCM(G-PCM) devices have ∼40% lower RESET current compared to controldevices without the graphene. This is attributed to the graphene asan added interfacial thermal resistance which helps confine the generatedheat inside the active PCM volume. The G-PCM achieves programmingup to 105cycles, and the graphene could further enhancethe PCM endurance by limiting atomic migration or material segregationat the bottom electrode interface. [ABSTRACT FROM AUTHOR]