science picBeforeHand aims at realizing chalcogenide heterostructures, aiming to provide a processing/storage, all-in-one device, to be embedded in automotive IoT smart devices.

Why using chalcogenide multilayers?

The basic idea is to create multilayers of chalcogenides of different alloy and compound combinations. The PCM cell takes advantage of the merits of the different sorts of materials used for the stack. To be more concrete, let us consider to choose a material with the ability to enhance the write speed (reduce the latency); then it must have a high crystallization speed. However, such materials often suffer from poor thermal stability (low retention). The dilemma between speed and stability is in practice solved by sacrificing the speed to assure the cell thermal stability. In recent time, research on superlattice structures of alternating Sb2Te3 and GeTe or GST revealed not only higher speed than GST, but also a better thermal stability than Sb2Te3 films is expected, although an experimental verification is missing. This shows that combining layers of materials with different physical properties might help to achieve the best material trade-off.

Here we aim at designing unusual active storage/processing layers through functionalization study of proper multilayer heterostructures. Alternated materials will be combined with classical planar and novel geometries, such as core-shell nanowires (NWs). Self-assembled NWs will be used as models to explore innovative cell configurations. NWs help to better understand the complex relationships between structure, interfaces and properties in such PCM multilayers.