Multi-Level Non-Volatile Memory

The advent of two-dimensional (2D) materials has opened a range of new opportunities in accessing ultra-scaled device dimensions for future logic and memory applications.  We have recently demonstrated that a single layer of large-area chemical vapor deposition-grown molybdenum disulfide (MoS2) sandwiched between two metal electrodes can be tuned to show multilevel nonvolatile resistive memory states with resistance values separated by 5 orders of magnitude. The switching process is unipolar and thermochemically driven requiring significant Joule heating in the reset process. (See Figure 1)

The multi-level non-volatile memory exhibited by the metal-MoS2-metal structure is of particular interest to the realisation of dedicated neuromorphic hardware as in has the potential to represent the weighting function in a back propagation ANN reducing the complexity and energy consumption in AI tasks. 

Figure 1: MoS2 2D Device exhibiting multi-level, non-volatile resistive memory states.

Reference: Shubhadeep Bhattacharjee, Enrico Caruso, Niall McEvoy, Cormac Ó Coileáin, Katie O’Neill, Lida Ansari, Georg S. Duesberg, Roger Nagle, Karim Cherkaoui, Farzan Gity, and Paul K. Hurley, “Insights into Multilevel Resistive Switching in Monolayer MoS2”, ACS Appl. Mater. Interfaces 2020, 12, 5, 6022–6029