High performance vertically integrated double barrier AlN memristive nonvolatile resistive random-access memory

Abstract

As one of the most promising high-speed nonvolatile memristors, aluminum nitride-based memristors have shown ultrafast switching at or even below nanoseconds. However, the on/off ratio, lifespan, and endurance of nitride memristors are very limited due to their intrinsic nitrogen vacancy conduction. Here, we demonstrate that memristors built on wide bandgap semiconductor aluminate nitride AlN possessed a representative prototypical digital memristive behavior through device structure optimization. The on/off ratio of the AlN memristors could be improved to 106 using one device cell, which consists of two memristors connected in parallel with a common bottom electrode. We identified space charge limited conduction in the low resistance state and Schottky emission in the high resistance state as the dominant conduction mechanisms. The AlN-based memristors could transform to volatile memory by reducing the interfacial barrier height. We further designed and fabricated a vertically integrated double barrier AlN memristor as a nonvolatile ReRAM on 2-in. sapphire and silicon wafers. These integrated double barrier AlN memristors possess high performance with an endurance of 104, a retention of 105 s, and clear switching threshold voltages, indicating a promising nonvolatile memory.