Investigation on thermal stability of vanadium-doped Sb2Te phase change material

Abstract

Transition metal elements doping can greatly improve the usability of Sb–Te for phase change memory. In this paper, we focused on the thermal stability of transition vanadium (V)-doped Sb2Te (VSb2Te) films with different V concentration which were prepared by co-sputtering. The effects of V doping on the crystallization and microstructure properties of Sb2Te were studied by temperature-dependent resistance measurements, in-situ heating TEM and HRTEM observation, respectively. With increasing V content, the crystallization is inhibited and the data retention is obviously enhanced, and the grain size shrinks significantly. Ab initio molecular dynamics simulation was used to explain the mechanism of the improved thermal stability and the results show that the diffusion of Sb and Te atoms are suppressed by doped V, which may account for the high thermal stability of VSb2Te.