A multilevel phase-change memory cell that is based on a CrGeTe(CrGT)/ HfGeSb(HfGS) superlattice-like (SLL) structure is proposed. With increasing temperature in resistance-temperature tests, the SLL thin films exhibit a threestep phase-change process that corresponds to the crystallization of Sb, GeTe, and CrGeTe. A stable and reversible three-step phase change is identified as the key characteristic for realizing multilevel storage. This so-designed multiplecrystallization SLL structure is a feasible way to increase the storage density.
For high-performance data centers, huge data transfer, reliable data storage and emerging in-memory computing require memory technology with the combination of accelerated access, large capacity and persistence. As for phase-change memory, the Sb-rich compounds Sb7Te3 and GeSb6Te have demonstrated fast switching speed and considerable difference of phase transition temperature. A multilayer structure is built up with the two compounds to reach three non-volatile resistance states. Sequential phase transition in a relationship with the temperature is confirmed to contribute to different resistance states with sufficient thermal stability. With the verification of nanoscale confinement for the integration of Sb7Te3/GeSb6Te multilayer thin film, T-shape PCM cells are fabricated and two SET operations are executed with 40 ns-width pulses, exhibiting good potential for the multi-level PCM candidate.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.