Growth-dominant Sb2Te material with large crystal grain is converted to the nano composite material after Si doping. The increase of Si content in SixSb2Te material helps to further diminish the grain size, form more uniform grain distribution, and enhance the thermal stability of the amorphous phase. Si2Sb2Te crystallizes into a nano composite structure [amorphous Si + crystalline Sb2Te (<20 nm grain size)] without any Te or Sb phase segregation, which ensures better operation stability for the application in T-shaped phase change memory device. Comparing to Ge2Sb2Te5 film, Si2Sb2Te film shows better data retention ability (10 years at 397 K). Meanwhile, electrical measurements prove that phase change memory cell based on Si2Sb2Te film also has low power consumption than that of the Ge2Sb2Te5 film based cell. (C) 2011 Elsevier B.V. All rights reserved.