Structure and Electrical Properties of Ge2Sb2Te5 Thin Film Used for Ovonic Unified Memory
ZHANG Ting1, LIU Bo1, XIA Ji-Lin1, SONG Zhi-Tang1, FENG Song-Lin1, CHEN Bomy2
1Research Center of Functional Semiconductor Film Engineering and Technology, State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050
2Silicon Storage Technology, Inc. 1171 Sonora Court, Sunnyvale, CA 94086, USA
Structure and Electrical Properties of Ge2Sb2Te5 Thin Film Used for Ovonic Unified Memory
1Research Center of Functional Semiconductor Film Engineering and Technology, State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050
2Silicon Storage Technology, Inc. 1171 Sonora Court, Sunnyvale, CA 94086, USA
Abstract: Annealing temperature effects on the structure and electrical resistance of Ge2Sb2Te5 thin film were studied. The crystallization and melting temperature of the thin film are about 175°C and 610°C respectively. The structure of the as-deposited and the annealed film at different annealing temperatures are identified by the x-ray diffraction method. The thin film changes from an amorphous state to the fcc structure at about 200°C, and then changes into the hexagonal close-packed (hcp) structure at about 400°C. Electrical resistance of as-deposited thin film reaches as high as 1.7 x 108 Ω/sq. Then it decreases to 1.6 x 104 Ω/sq and 165 Ω/sq after the annealing process at 250°C and 400°C respectively. The current-voltage curve of the Ge2Sb2Te5 thin film is also investigated. Due to the large resistance difference between the amorphous, the fcc crystalline and the hcp crystalline states, Ge2Sb2Te5 film may be used to realize multilevel storage for Ovonic unified memory.
ZHANG Ting;LIU Bo;XIA Ji-Lin;SONG Zhi-Tang;FENG Song-Lin;CHEN Bomy. Structure and Electrical Properties of Ge2Sb2Te5 Thin Film Used for Ovonic Unified Memory[J]. 中国物理快报, 2004, 21(4): 741-743.
ZHANG Ting, LIU Bo, XIA Ji-Lin, SONG Zhi-Tang, FENG Song-Lin, CHEN Bomy. Structure and Electrical Properties of Ge2Sb2Te5 Thin Film Used for Ovonic Unified Memory. Chin. Phys. Lett., 2004, 21(4): 741-743.