The Bi and Sn were doped to Ge2Sb2Te5 (GST) to investigate and modify the phase transition characteristics. The Bi/Sn doped GST thin film was prepared by RF magnetron co-sputtering and its crystal structure, sheet resistance, and phase transition kinetics were analyzed. By the doping of Bi/Sn, the crystallization temperature or stable phase was changed slightly compared with GST. For the PRAM application, the optimum doping concentration was Bi 5.9 and Sn 17.7 at.%, and its minimum time for crystallization was shorten more than 30% compared with GST. The sheet resistance difference between amorphous and crystalline state was higher than 104 WE. (c) 2006 Elsevier B.V. All rights reserved.