Improvement of Multilevel Memory Performance of MnTe Thin Films by Ta Doping

The pressing need for data storage in the era of big data has driven the development of new storage technologies. As a prominent contender for next-generation memory, phase-change memory can effectively increase storage density through multilevel cell operation and can be applied to neuromorphic and in-memory computing. Herein, the structure and properties of Ta-doped MnTe thin films and their inherent correlations are systematically investigated. Amorphous MnTe thin films sequentially precipitated cubic MnTe₂ and hexagonal Te phases with increasing temperature, causing resistance changes. Ta doping inhibited phase segregation in the films and improved their thermal stability in the amorphous state. A phase-change memory cell based on a Ta_2.8%-MnTe thin film exhibited three stable resistive states with low resistive drift coefficients. The study findings reveal the possibility of regulating the two-step phase-change process in Ta-MnTe thin films, providing insight into the design of multilevel phase-change memory.