Repeatable, accurate, and high speed multi-level programming of memristor 1T1R arrays for power efficient analog computing applications.

Beyond use as high density non-volatile memories, memristors have potential as synaptic components of neuromorphic systems. We investigated the suitability of tantalum oxide (TaOx) transistor-memristor (1T1R) arrays for such applications, particularly the ability to accurately, repeatedly, and rapidly reach arbitrary conductance states. Programming is performed by applying an adaptive pulsed algorithm that utilizes the transistor gate voltage to control the SET switching operation and increase programming speed of the 1T1R cells.

Direct Observation of Localized Radial Oxygen Migration in Functioning Tantalum Oxide Memristors.

Oxygen migration in tantalum oxide, a promising next-generation storage material, is studied using in operando X-ray absorption spectromicroscopy. This approach allows a physical description of the evolution of conduction channel and eventual device failure. The observed ring-like patterns of oxygen concentration are modeled using thermophoretic forces and Fick diffusion, establishing the critical role of temperature-driven oxygen migration.

Voltage divider effect for the improvement of variability and endurance of TaO(x) memristor.

The impact of a series resistor (R(S)) on the variability and endurance performance of memristor was studied in the TaO(x) memristive system. A dynamic voltage divider between the R(S) and memristor during both the set and the reset switching cycles can suppress the inherent irregularity of the voltage dropped on the memristor, resulting in a greatly reduced switching variability. By selecting the proper resistance value of R(S) for the set and reset cycles respectively, we observed a dramatically improved endurance of the TaO(x) memristor.