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

Phase transition behaviors of Ga30Sb70/Sb80Te20 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 Ga30Sb70. The exponential increase of crystallization temperature can reach as high as 130 °C when the layer thickness of Sb80Te20 was reduced to 4 nm. Furthermore, by adjusting the layer thicknesses of Ga30Sb70 and Sb80Te20, the crystallization temperature of the multilayer films can be accurately controlled. The results of cross-sectional analysis using transmission electron microscopy (TEM) confirmed that Ga30Sb70/Sb80Te20 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 Ge2Sb2Te5 film.

► The crystallization temperature increased with increasing Ga30Sb70 layer thickness.
► The crystallization temperature increased with decreasing Sb80Te20 layer thickness.
► Ga30Sb70/Sb80Te20 multilayer films have lower RESET voltage values than Ge2Sb2Te5.