An experimental study of Ge diffusion through Ge2Sb2Te5

Ge thermal diffusion is not only the phenomenon limiting decomposition and crystallization of Ge-rich GeSbTe alloys but also responsible for some failures phase change memory devices using them. However, in canonical Ge2Sb2Te5 (GST-225) or (GGST) has been little studied experimentally. For these reasons, we have designed set up a series experiments aimed at highlighting studying this within solid phase, under technologically relevant conditions. that, dedicated GST/Ge/GST structures grown purpose, redistribution GST-225 layers during isothermal isochronal annealing scanning transmission electron microscopy based techniques. While amorphous negligible low temperatures (i.e., below 140 °C), it fast crystalline above 220 °C proceeds via grain boundaries. During such annealing, limited by emission atoms from source density boundaries providing paths to through polycrystalline layer, which tends decrease as function time GST grains coalesce. These results show that phenomena can be activated moderate chemical composition morphology Ge/GST composite materials. This supports hypothesis may observed resistance drift loss integrity Phase Change Memories on SET state.