Temperature‐Dependent Thermal Conductivity and Interfacial Resistance of Ge‐Rich Ge₂Sb₂Te₅Films and Multilayers

Abstract

This article reports on the thermal characterization of Ge‐rich Ge 2 Sb 2 Te 5 films and Ge 2 Sb 2 Te 5 /Ge‐rich Ge 2 Sb 2 Te 5 multilayers designed for high‐temperature applications in the field of phase‐change memory. The thermal conductivities of such materials and the thermal boundary resistance with the Si 3 N 4 dielectric material are characterized by two different photothermal techniques. The phase change in Ge‐rich Ge 2 Sb 2 Te 5 is found to occur at a temperature higher than that of the Ge 2 Sb 2 Te 5 alloy. The Ge 2 Sb 2 Te 5 /Ge rich Ge 2 Sb 2 Te 5 multilayer has been observed to feature two phase changes corresponding to Ge‐rich Ge 2 Sb 2 Te 5 and Ge 2 Sb 2 Te 5 . Finally, it is estimated that the thermal resistance of the interface separating Ge‐rich Ge 2 Sb 2 Te 5 and Ge 2 Sb 2 Te 5 nanolayers constitutes the multilayer structure and its contribution has been realized to be significant in enhancing the thermal resistance of the multilayer structure.