Ag掺杂对Ge2Sb2Te5结晶行为的影响

Ag掺杂对Ge₂Sb₂Te₅结晶行为的影响

张 滔¹，郑 坤^1*，张 斌¹，邵瑞文¹，韩晓东¹，张 泽^1，2

（1．北京工业大学固体微结构与性能研究所，北京 100124;

2．浙江大学电镜中心，材料科学与工程学系，浙江 杭州 310027）

摘  要：通过磁控溅射仪制备了Ge₂Sb₂Te₅(GST)和Ag_10.6(GST)_89.4薄膜，利用X射线衍射（XRD）、电阻-温度（R-T）测试、透射电子显微学以及径向分布函数（RDF）等方法对比研究了GST和Ag_10.6(GST)_89.4的结晶过程和微观结构及其演化的差异。发现掺Ag的薄膜非晶态、晶态电阻均比GST更高，而且结晶过程只有非晶相到面心立方相（fcc）的转变，没有出现GST的非晶到fcc再到六方相（hcp）的过程，XRD分析进一步证实了这一结果。同时，透射电镜原位加热实验证实了在300℃时，Ag_10.6(GST)_89.4仍然保持着fcc结构，而GST中已经出现了hcp相。通过统计230℃下时效处理的晶态薄膜的晶粒尺寸，发现Ag_10.6(GST)_89.4的平均晶粒尺寸小于Ge₂Sb₂Te₅薄膜的，这可能是造成其晶态电阻高于GST的主要原因。

关键词：Ag掺杂; GeSbTe; 相变材料；磁控溅射；透射电镜

        中图分类号：TB34；TG111.5；TG115.21⁺5.3       文献标识码：A        doi:10.3969/j.1000-6281.2014.01.001

Crystallization behavior of phase change material Ge₂Sb₂Te₅ doped with Ag

ZHANG Tao¹，ZHENG Kun^1* ，ZHANG Bin¹，SHAO Rui-wen¹，

HAN Xiao-dong¹，ZHANG ze^1，2

（1．  Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology，  Beijing 100124；2．Department of Materials Science，Zhejiang University，Hangzhou Zhejiang 310027，China）

Abstract：Ag-doped Ge₂Sb₂Te₅ films have been prepared, and the influence of Ag doping on the crystallization behavior, structure was investigated through X-ray diffraction techniques, electrical resistivity measurement and in situ TEM annealing techniques. The results show that the addition of Ag into GST films could result in an enhancement in electrical resistance compared with Ge₂Sb₂Te₅ films. Ag doping can lead to one-step crystallization process from amorphous to single face-centered cubic (fcc) phase without any other crystalline phase. HRTEM images show that the grain size in Ag-doped Ge₂Sb₂Te₅  films is smaller than that in conventional Ge₂Sb₂Te₅  films.

Keywords：Ag doping; GeSbTe; phase change materials；magnetron sputtering；transmission electron microscope

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