GeTe/Sb2Te3 superlattices (SLs) obtained by sputtering are integrated in phase‐change memory (PCM) devices with a “wall structure”. The high structural quality of SLs deposited on TiN or SiNx layers, used as metallic bottom heater and dielectric bottom layer in PCM devices, is established by X‐ray diffraction, for as‐grown SLs and after an annealing corresponding to the maximum thermal budget during the integration process. Scanning transmission electron microscopy (STEM) images of SLs within PCM cells confirm that the SL structure is kept after integration. A robust statistical analysis on a large number of devices demonstrates unambiguously that the RESET current is lower in SL devices than in GeTe reference devices and decreases when the Sb2Te3 layer thickness in the SL increases from 2 to 8 nm. STEM imaging of a PCM cell incorporating an SL demonstrates that switching from the low‐ to the high‐resistance state occurs through a melting–quenching process and is not due to crystal–crystal transition or defect reorganization in the SL, in contrast to what is commonly stated in the literature on interfacial phase‐change memories (iPCMs). The origin of the improved switching performance of SL‐based PCM devices is discussed, linked with the impact of swapped bilayers.

Sb2Te3 is a layered material with outstanding properties leading to applications in interfacial phase-change memories, spintronic and thermoelectric devices. For successful integration in devices, controlling the orientation of the atomic planes of Sb2Te3 deposited by sputtering on various materials used for electrodes and on dielectric layers is required. We have succeeded in depositing Sb2Te3 thin films (thickness in the range 10–100 nm) by sputtering in industrial deposition equipments on WSi, TiN, amorphous Si as well as on native and thermal silicon oxide layers. The structure and orientation of the films were studied by x-ray diffraction. The Sb and Te planes are found parallel to the substrate, whatever the nature of the bottom material, provided that the sputtering conditions avoid a Te deficiency in the deposited film. These results show that deposition of Sb2Te3 with out-of-plane orientation on silicon oxide is actually possible, in contrast with previous literature results. Scanning transmission electron microscopy images of the interface between the Sb2Te3 film and the bottom material allow to elucidate the growth mechanism. The formation of a surface layer containing a few Te planes on top of the bottom material is mandatory for the subsequent growth of an out-of-plane oriented Sb2Te3 film by van der Waals epitaxy.