Layer thickness dependence of the phase separation and phase change properties of Ge2Sb2Te5/TiN superlattice-like thin films

Abstract The dependence on the layer thickness of the structural and phase change properties of Ge 2 Sb 2 Te 5 /TiN superlattice-like thin films are investigated. The phase separation of binary Sb 2 Te 3 and GeTe phases is investigated using X-ray diffraction and Raman spectral analysis. The Ge 2 Sb 2 Te 5 /TiN interface is believed lead to phase separation, as well as the interface effects that facilitate the phase separation process in the superlattice-like films. In this investigation of the phase change properties, the critical temperature, 10-year lifetime temperature, phase change speed, and optical band gap are measured. We found that the phase change properties of Ge 2 Sb 2 Te 5 are greatly improved by increasing the layer thickness as a result of the phase separation suppression in the structure. This superlattice-like thin film may have potential in high-speed phase change memory applications.