Co-doping: An effective strategy for developing stable and high-speed Sb₂Te-based phase-change memory

Balancing operation speed and thermal stability is a big challenge in phase change memory (PCM). In this work, a carbon (C) and chromium (Cr) co-doped Sb₂Te strategy has been proposed for achieving high operation speed and high stability in PCM applications. In general, doping with the appropriate Cr element is beneficial to improve thermal stability, but it will sacrifice its operation speed. C-doping can enhance thermal stability and retain its fast phase transition properties due to the carbon elements tend to form agglomerates in the host that ameliorate disorder of the amorphous phase without loss of the phase transition rate. Intriguingly, the as-prepared C_1.19Cr_0.23Sb₂Te material exhibits good data retention (T_10-year @ 155.0 °C) and low-volume change rate (1.8%), as well as fast switching speed (4 ns) and good endurance (>1 × 10⁵ cycles). This research indicates that C and Cr co-doping is an effective method to achieve excellent stability of phase-change materials without sacrificing the phase-transition rate of Sb₂Te materials.