Fast crystallization and low power of Al-doped Sn2Se3 thin films for phase change memory applications

Abstract

Phase change behavior in Al-doped Sn2Se3 thin films were investigated by utilizing in situ resistance measurements. It is found that the crystallization temperature and resistance increase with increasing of Al content. AFM images demonstrated Al-doping reduced the surface roughness and inhibited the crystallization of Sn2Se3 thin films. A smaller density change before and after phase change for Al0.023(Sn2Se3)0.977 thin films was obtained from X-ray reflectivity. The phase transition speed between the amorphous and crystalline state was investigated by the picosecond laser pulses. The obtained values of Avrami indexes indicate that a one dimensional growth-dominated mechanism is responsible for the set transition of Al0.023(Sn2Se3)0.977 thin film. Phase transition is observed at relatively lower power, compared with a device using Ge2Sb2Te5 film.