Understanding the Effects of Ta Doping in Sb₂Te₃ for High‐Performance Phase Change Memory

Abstract Phase change memory is a leading candidate for storage class memory (SCM). Among various phase‐change materials, Sb‐Te‐based materials, which have high‐speed operation characteristics, are actively studied. Herein, a high‐performance phase‐change material is designed for doping tantalum (Ta) inside Sb 2 Te 3 (ST). To optimize the Ta doping concentration, Ta‐doped ST films with various Ta concentrations are fabricated using a sputtering process. The phase change characteristics of the fabricated Ta‐doped ST films of various concentrations are analyzed, and the crystallographic, structural, and electrical effects of Ta doping inside Sb 2 Te 3 are analyzed. Analysis of the Ta doping effect on Sb 2 Te 3 shows that the crystallization temperature of the ST‐based phase‐change material increased and that grain growth is suppressed, thereby affecting electrical conductivity. Consequently, the optimized Ta doping concentration as a phase‐change material is obtained. A phase change memory device is fabricated using optimized Ta(0.41):ST and confirmed to have fast set speed (≈15 ns) and low resistance drift characteristics. Through this study, the Ta doping effect of Sb 2 Te 3 is extensively analyzed, and the optimal Ta doping concentration is demonstrated. It is confirmed that Ta‐doped ST is a high‐performance phase‐change material applicable to next‐generation SCM.