Large-area multilayer molybdenum disulfide for 2D memristors

Abstract

Resistive random access memories (RRAMs) using two-dimensional (2D) materials have delivered comparable switching performance with CMOS devices. However, devices risk short problems because of their ultra-thin body, thus yielding poorly. In this study, we realize high-yield RRAMs thanks to the synthesis of uniform large-area multilayer molybdenum disulfide by thermally decomposing ammonium tetrathiomolybdate. This top-down method has advantages over mainstream chemical vapor deposition, in which layer-by-layer epitaxy is forbidden when surface energy elevates. The resulting film surface roughness is down to 93.8 pm, and its lateral size can be scaled up to wafer scale. A yield value higher than 90% was estimated by testing 8 × 8 RRAM arrays, reaching nearly 100% in isolated devices. These devices show low operation voltages (∼1V) with low cycle-to-cycle and device-to-device variations (∼12%). We also observed stable resistive switching of multilayer films prepared at 400 °C. The large-area synthesis of uniform multilayer films makes it more feasible to use 2D semiconductors in practical RRAM technology for wafer-scale integration.