Nano composite Si2Sb2Te film for phase change memory

Growth-dominant Sb₂Te material with large crystal grain is converted to the nano composite material after Si doping. The increase of Si content in Si_xSb₂Te 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.