Phase transition behaviors of Ga30Sb70/Sb80Te20 nanocomposite multilayer films for application in phase change random access memory

Abstract Phase transition behaviors of Ga 30 Sb 70 /Sb 80 Te 20 nanocomposite multilayer films were investigated for potential use in phase change random access memory (PCRAM). The temperature dependence of sheet resistance measurements were employed to study the phase transition behaviors of the multilayer films. It was found that the crystallization temperature of the multilayer films increased monotonously with increasing the layer thickness of Ga 30 Sb 70 . The exponential increase of crystallization temperature can reach as high as 130 °C when the layer thickness of Sb 80 Te 20 was reduced to 4 nm. Furthermore, by adjusting the layer thicknesses of Ga 30 Sb 70 and Sb 80 Te 20 , the crystallization temperature of the multilayer films can be accurately controlled. The results of cross-sectional analysis using transmission electron microscopy (TEM) confirmed that Ga 30 Sb 70 /Sb 80 Te 20 multilayer films had layered structures with clear interfaces. Phase transition from crystalline (SET) to amorphous (RESET) states was observed to occur at relatively lower RESET voltages, as compared with a device using Ge 2 Sb 2 Te 5 film.