Controllable crystallization and enhanced amorphous stability of Sb–Te films modified by Ag-doping

Ag-doped Sb–Te films were deposited by magnetron co-sputtering and the structure, electrical, optical and thermal properties were analyzed. The results show that Ag-doping restrains crystal grain size, and changes a preferred orientation of the crystalline phase. The crystallization temperature is increased due to the Ag addition. Both amorphous resistance and crystalline resistance are enhanced and the resistance ratio reaches ~104. Compared with Ge2Sb2Te5, Ag26.82(Sb3Te)73.18 film exhibits a better amorphous thermal stability, a higher crystallization temperature (~166 °C), a wider optical band gap (0.515 eV), a larger crystallization activation energy (3.17 eV) as well as a better 10 years data retention at 92 °C.