Thermal conductivity measurement of Ge2Sb2Te5 thin film using improved 3 omega method

Abstract

Understanding how heat is transferred in nanostructured materials is essential for improving nanoscale devices and developing novel devices. In particular, the measurement and analysis of heat transfer in phase change random access memories (PCRMs) are important, because this local heat transfer determines the development and innovation of PCRMs. In this study, we improved the existing 3 omega method to measure the thermal conductivity of a nanoscale thin film composed of Ge2Sb2Te5 (GST), whose thermal conductivity is changed by the limitation of phonons' transport. The heat transfer of the thin GST film was analyzed by applying the phonons' kinetic theory (gray model) and measurement results from the improved 3 omega method. The measured thermal conductivity of GST and the improved 3 omega method are expected to be used in the phase change random-access memory industry for developing novel devices.