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. (© 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)