Excellent thermal stability owing to Ge and C doping in Sb 2 Te-based high-speed phase change memory

The contradictory nature between transition speed and thermal stability of phase change materials has always been the key limitation to achieve wide applications under the harsh condition. Ge2.3Sb2.0Te phase change alloy is proposed here to feature high thermal stability (10-year data retention above 220 oC) and fast switching speed (SET programming speed up to 5 ns) for the electronic storage. In mushroom-shaped device cells, the nanocomposite materials implement an endurance life nearly 1×105 cycles. Such operation speed among alloys with high-temperature characteristic is the best ever reported. And the moderate incorporation of C offers intriguing benefits that include the enhanced thermal stability and reduced RESET voltage in above Ge-rich Sb2Te-based memory cells. Through microscopic analysis, the local segregation of C dopants can further refine crystalline grains and thus induce a less volume change and roughness upon heating process. These properties are crucial regarding the application potential in high-performance and high-density embedded memories.