Intrinsic Confinement in Carbon-Doped In–Sb–Te Materials Enabling High Thermal Stability and Reliability of Phase-Change Memory

Achieving both high thermal stability and rapid switching remains a significant challenge for phase-change materials employed in high-temperature memory applications. In this study, we present a carbon-doped In–Sb–Te (CInST) phase-change material that combines fast switching characteristics inherent to In–Sb–Te material with enhanced thermal stability imparted by carbon-induced confinement. The incorporation of carbon atoms effectively suppresses grain growth, resulting in a refined and thermally stable crystalline microstructure while maintaining the coherent In–Te and Sb–Te octahedral framework during phase transitions. The CInST film demonstrates a crystallization temperature of 256 °C and a 10 year data retention temperature of 160 °C. The phase-change memory devices based on CInST material exhibit a substantial reduction in programming voltages compared to those utilizing Ge 2 Sb 2 Te 5 . Furthermore, these devices achieve a rapid switching speed of 6 ns and demonstrate robust cycling endurance exceeding 10 6 cycles. Remarkably, the devices maintain switching endurance beyond 5 × 10 5 cycles after high-temperature annealing at 400 °C. These findings elucidate the cooperative effects of carbon-induced grain confinement and geometrically matched octahedral scaffold in enhancing the thermal stability and reliability of In–Sb–Te phase-change materials, thereby offering a promising design strategy for high-temperature phase-change memory technology.