Epitaxial phase-change materials

Epitaxial $ {\rm Ge}_{2} {\rm Sb}_{2} {\rm Te}_{5} $ thin layers were successfully grown in the metastable cubic phase on both slightly lattice‐mismatched (GaSb) and highly lattice‐mismatched (Si) templates. The higher quality of the films grown on (111)‐oriented substrates is attributed to the tendency to form layered structures in the stable bulk phase as well as to the nature of distortion in the metastable cubic phase. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) Rodenbach, Calarco and co‐workers report the successful epitaxial growth of the phase‐change material Ge2Sb2Te5 (GST) on GaSb(001), GaSb(111), and Si(111) using molecular beam epitaxy. The structural properties are investigated by reflection high energy electron diffraction, synchrotron X‐ray diffraction and transmission electron microscopy. The films exhibit a superior quality if grown on (111) surfaces, independent of the lattice mismatch. This is attributed to the tendency of this material to form layered structures as well as to the nature of distortion in the metastable cubic phase.