Investigation on the Scaling Performances of Carbon‐Doped Ge ₂ Sb ₂ Te ₅ Thin Films for Phase Change Random Access Memory in a 40 nm Process

Herein, the amorphous and crystalline characteristics at different thicknesses for carbon‐doped Ge 2 Sb 2 Te 5 (CGST) thin films are systematically investigated. Switching current and grain size of the cubic (face‐centered cubic [FCC]) phase both reduce in thinner films, and the 35 nm‐thick CGST‐based chips can even switch in just 30 ns. Interestingly, high data retention (118 °C) is also maintained in 35 nm‐thick CGST‐based chips, better than the case in Ge 2 Sb 2 Te 5 ‐based chips (85 °C). The endurance ability of more than 10 7 cycles with a resistance ratio of one order of magnitude demonstrates that the 35 nm‐thick CGST‐based chip is a potential candidate for the application of phase change random access memory.