Multilayered Sb-Rich GeSbTe Phase-Change Memory for Best Endurance and Reduced Variability

Sb-rich GeSbTe-based phase-change memories (PCMs) were studied in the past years for their high switching speed to target storage class memory (SCM) applications. In this work, we show the advantages of an engineered multilayered Sb-rich GeSbTe stack compared with standard bulk reference materials. The studied multilayer-based PCM devices feature a lower programming current with respect to the equivalent bulk ones, preserving a high programming speed. Furthermore, multilayered Sb-rich GeSbTe brings better endurance performances for a wide programming current range and extremely reduced cycle-to-cycle (C2C) and device-to-device (D2D) variability along cycling verified in 4 kb PCM arrays. These results confirm improved yield and reliability obtained, thanks to multilayered PCM solution.