Phase change in GeTe/Sb2Te3 superlattices: Formation of the vacancy-ordered metastable cubic structure via Ge migration

In this study a large-area phase change was performed using optical laser pulsing to demonstrate the formation of metastable face-centered cubic GeSbTe blocks in the reset state of iPCM resulting from the Ge atom rearrangement to the pre-existing vacancy layers, which will be the basis for the phase-transition mechanism of next generation non-volatile memory devices.