Multi-step phase-change behavior in Ga30Sb70/SnSe2 nanocomposite multilayer thin films

摘要

Multi-step phase-change behavior in Ga30Sb70/SnSe2 nanocomposite multilayer films was investigated for multi-level storage in phase change random access memory in order to increase its storage density. It can be found in the temperature-dependent resistance curves that multi-step phase change happened at the temperature of 210 °C and 270 °C, respectively, which can provide the possibility of high temperature storage. At the constitute of [Ga30Sb70(10 nm)/SnSe2(15 nm)]2 and [Ga30Sb70(25 nm)/SnSe2(25 nm)]1, the nanocomposite multilayer films show well resistance gap between amorphous and crystalline state, which represent the on/off ratios in practical devices and better multi-step prosperities in archival life stability compared to Ge2Sb2Te5 films. The analysis of both XRD patterns and TEM images confirmed the two step phase change in Ga30Sb70/SnSe2 nanocomposite multilayer films. The Ga30Sb70/SnSe2 nanocomposite multilayer film is a promising phase change materials in high density storage device.