Etch damage of Ge 2 Sb 2 Te 5 (GST) has been investigated after etching in halogen inductively coupled plasmas (ICPs) such as CF 4 , Cl 2 , and HBr. X-ray photoelectron spectra of Ge, Sb, and Te on the etched surfaces showed different depths of etch damage depending on the halogen-based plasmas. The blank GST etched by CF 4 showed a lower total-halogen-percentage remaining on the etched surface than that etched by Cl 2 even though the depth of halogenations was the deepest for the GST etched by CF 4 owing to the highest reactivity. However, when a GST feature masked by SiO 2 /Ti/TiN was etched, owing to the reaction of O from the SiO 2 mask and C from CF 4 , a thinner/or no C–F polymer appeared to be formed on the etched sidewall; therefore, the highest halogenation was observed on the GST etched by CF 4 . Among the halogen-gases investigated, HBr showed the lowest damage due to the lowest reactivity.