Influence of doping upon the phase change characteristics of Ge2Sb2Te5
Influence of doping upon the phase change characteristics of Ge2Sb2Te5
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DOI：
10.1007/s00542-006-0156-5
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发表时间：
2006-11
期刊：
影响因子：
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通讯作者：
K. Wang;C. Steimer;D. Wamwangi;S. Ziegler;M. Wuttig;J. Tomforde-;W. Bensch
中科院分区：
文献类型：
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作者：
K. Wang;C. Steimer;D. Wamwangi;S. Ziegler;M. Wuttig;J. Tomforde-;W. Bensch
采用四点探针电阻测量、掠射x射线衍射（XRD）、x射线反射（XRR）、变入射角光谱椭偏仪（VASE）和静态测试仪等多种技术研究了掺杂对Ge2Sb2Te5（GST）相变特性的影响。Bi、Sn或In的掺杂保持了GST的nacl型晶体结构，但由于原子半径更大，使得晶格扩大。充分的光学对比显示，可以推测与结晶时明显的密度变化有关。在Bi和Sn掺杂情况下，相对于未掺杂情况，转变温度降低。在10ns内实现了超快速结晶，这与单一的nacl结构相和较弱的键引起的较低的转变温度有关。然而，在掺杂的情况下，结晶被延迟，这可能与所观察到的相分离和升高的转变温度有关。
The influence of doping upon the phase change characteristics of Ge2Sb2Te5(GST) has been determined with a variety of techniques including four-point-probe electrical resistance measurements, grazing incidence X-ray diffraction (XRD), X-ray reflectometry (XRR) and a variable incident angle spectroscopic ellipsometer (VASE) and a static tester. Doping with Bi, Sn or In maintains the NaCl-type crystalline structure of GST but expands the lattice due to the larger atomic radii. Sufficient optical contrast is exhibited and can be presumably correlated with the pronounced density change upon crystallization. In the Bi and Sn doped case transition temperatures are reduced with regard to the undoped case. Ultra-fast crystallization within 10 ns is demonstrated, which is correlated with a single NaCl-structure phase and a lower transition temperature arising from the weaker bonds. In the In doped case, however, crystallization is retarded, which can be correlated with the observed phase separation and the increased transition temperature.