Effect of Transition Metal Dichalcogenide Based Confinement Layers on the Performance of Phase-Change Heterostructure Memory

Abstract

Phase-change random-access memory is a promising non-volatile memory technology. However repeated phase-change operations can cause durability issues owing to defects formed by long-distance atom diffusion. To mitigate these issues, phase-change heterostructure (PCH) devices with confinement material (CM) layers based on transition metal dichalcogenides (TMDs) such as TiTe2 have been proposed. This study implements PCH devices with additional TMDs, including NiTe2 and MoTe2, alongside TiTe2, and analyzes their characteristics by examining the differences in the CM layers. The results show that the NiTe2-based PCH device demonstrates a RESET current of 1.4 mA, 38% lower than that of the TiTe2-based device, enabling low-power operation. Furthermore, the MoTe2-based PCH device exhibits a cycling endurance exceeding 107 cycles, a five-fold improvement in durability compare with the TiTe2-based device. The performance differences observe in each PCH device can be attributed to the variation in the material properties, such as the cohesive energy and electrical conductivity, of the TMDs used as the CM layer. These results provide critical clues to improve the performance and reliability of conventional PCH memory devices.