Germanium antimony telluride has been the most used and studied phase-change material for electronic memory due to its suitable crystallization temperature, amorphous to crystalline resistance contrast, and stability of the amorphous phase. In this work, the segregation of Ge in a Ge2Sb2Te5 film of 30 nm thickness during heating inside the transmission electron microscope was observed and characterized. The Ge2Sb2Te5 film was deposited using sputtering on a Protochips Fusion holder and left uncapped in atmosphere for about four months. Oxygen incorporated within the film played a significant role in the chemical segregation observed which resulted in amorphous Ge-O grain boundaries and Sb and Te rich crystalline domains. Such composition changes can occur when the phase-change material interfaces insulating oxide layers in an integrated device and would significantly impact its electrical and thermal properties.
@article{arxiv.2001.08100,
title = {Chemical segregation in Ge2Sb2Te5 thin films during in-situ heating},
author = {Shalini Tripathi and Paul Kotula and Manish Singh and Chanchal Ghosh and Gokhan Bakan and Helena Silva and Barry Carter},
journal= {arXiv preprint arXiv:2001.08100},
year = {2020}
}