Compositionally matched nitrogen-doped Ge2Sb2Te5/Ge2Sb2Te5 superlattice-like structures for phase change random access memory

A compositionally matched superlattice-like (SLL) structure comprised of Ge2Sb2Te5 (GST) and nitrogen-doped GST (N-GST) was developed to achieve both low current and high endurance Phase Change Random Access Memory (PCRAM). N-GST/GST SLL PCRAM devices demonstrated similar to 37% current reduction compared to single layered GST PCRAM and significantly higher write/erase endurances of similar to 10(8) compared to similar to 10(6) for GeTe/Sb2Te3 SLL devices. The improvements in endurance are attributed to the compositionally matched N-GST/GST material combination that lowers the diffusion gradient between the layers and the lower crystallization-induced stress in the SLL as revealed by micro-cantilever stress measurements. (C) 2013 AIP Publishing LLC.