Ge_2Sb_2Te_5/SnSe_2 nanocomposite multilayer thin films for phase change memory application

摘要

By nanocompositing Ge_2Sb_2Te_5 and SnSe_2, the electrical and thermal proprieties of Ge_2Sb_2Te_5/SnSe_2 multilayer films for phase change random access memory (PCRAM) are better than those of Ge_2Sb_2Te_5 films. The crystallization temperature rises and can be controlled. The resistance gap can reach approximately five orders of magnitude to ensure high data reliability. The activity energy (Ea) is more than 2.60 eV and the temperature for 10 year data retention reach 110℃. The analysis of both XRD patterns and TEM images confirmed the reversible phase change transition between amorphous and crystalline state in Ge_2Sb_2Te_5/SnSe_2 nanocomposite multilayer films. According to transient photoreflectance traces, the speed of crystallization process was about 33 ns. Among different Ge_2Sb_2Te_5/SnSe_2 multilayer films, the film constitute of [Ge_2Sb_2Te_5 (4 nm)/SnSe_2(10 nm)]_7 showed better properties and was manufactured by CMOS technology to phase change memory (PCM) cells. This result revealed that the Ge_2Sb_2Te_5/SnSe_2 nanocomposite multilayer film is a promising phase change material.