Reconfiguration of van der Waals-like Interface in Superlattice Phase Change Material for Data Storage and Computing

Superlattice phase change memory, composed of alternately stacked crystalline phase change layers of Sb 2 Te 3 and GeTe (GeTe/Sb 2 Te 3 ), significantly reduces the switching energy and time by restricting atomic movement during the phase transition process. To further enhance the switching performance of the memory device, this study proposes a sandwich structure consisting of Sb 2 Te 3 /Bi 2 Te 3 /Sb 2 Te 3 (ST/BT/ST) layers, achieved by reconfiguring the van der Waals-like interface, to replace the Sb 2 Te 3 layer of traditional GeTe/Sb 2 Te 3 superlattice phase change material. A highly textured GeTe/ST/BT/ST superlattice film is deposited using a back-end-of-line-compatible sputtering technique, resulting in sharp van der Waals-like interfaces. Electrical switching measurements of a prototype device incorporating the ST/BT/ST structure demonstrate a reduced switching voltage and enhanced stability across multiple resistance levels, accompanied by low resistance drift. Electrothermal simulations indicate that the observed low-power switching behavior arises from the material’s low thermal conductivity and reduced thermal dissipation within the sandwiched superlattice. These findings suggest that the proposed superlattice phase change material holds significant promise for applications in low-power data storage and non-von Neumann computing devices.