Correlation between the structural transformations and physical properties in Ge2Sb2Te5 thin films

Despite the successful application of Ge₂Sb₂Te₅ thin films in the phase change memory devices, many fundamental issues related to the crystallization process are not fully understood. Structure of as-deposited and annealed at 160 and 250 °C films were investigated by XRD and TEM methods: amorphous, fcc and hcp structures were determined, respectively. Temperature dependencies of the resistivity for planar samples were measured at different heating rates. Temperatures and activation energies of transformations were estimated. Correlation between the electrical, thermal properties, surface morphology and structural characteristics in Ge₂Sb₂Te₅ thin films was analyzed.