Fast crystallization and low power of Al-doped Sn_2Se_3 thin films for phase change memory applications

摘要

Phase change behavior in Al-doped Sn_2Se_3 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 Sn_2Se_3 thin films. A smaller density change before and after phase change for Al_(0.023)(Sn_2_ Se_3)_(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 Al_(0.023)(Sn_2Se_3)_(0.977) thin film. Phase transition is observed at relatively lower power, compared with a device using Ge_2Sb_2Te_5 film.