Postgrowth annealing effect on structural and optical properties of ZnO films grown on GaAs substrates by the radio frequency magnetron sputtering technique
Postgrowth annealing effect on structural and optical properties of ZnO films grown on GaAs substrates by the radio frequency magnetron sputtering technique
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DOI：
10.1063/1.1483371
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发表时间：
2002-06
影响因子：
3.2
通讯作者：
M. Ryu;S. Lee;M. Jang;G. Panin;T. Kang
中科院分区：
文献类型：
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作者：
M. Ryu;S. Lee;M. Jang;G. Panin;T. Kang
利用高分辨扫描电子显微镜和阴极荧光光谱研究了生长后退火对射频溅射法生长的ZnO薄膜性能的影响。在550 °C退火的薄膜在室温下显示出良好的取向柱状结构和强激子发射。通过透镜二次电子探测器测量发现，镓和砷从衬底向外扩散到ZnO薄膜中，会产生不同的二次电子掺杂对比度。扩展的结构缺陷，如ZnO中的亚晶界协助Ga从GaAs衬底的外扩散，并显示出减少退火后的二次电子（SE）发射，而作为掺杂的ZnO相邻的ZnO/GaAs界面表现出增强的SE发射和增强的发光与施主-受主对和激子绑定到受主。
High-resolution scanning electron microscopy and cathodoluminescence spectroscopy measurements were performed to study the effect of postgrowth annealing on properties of ZnO films grown on GaAs substrates by rf sputtering. The films annealed at 550 °C show a well-oriented columnar structure and strong exciton emission at room temperature. Outdiffusion of gallium and arsenic from substrate into a ZnO film has been found to result in a different secondary electron dopant contrast, measured by the through-the lens secondary electron detector. Extended structural defects such as subgrain boundaries in ZnO assist Ga outdiffusion from the GaAs substrate and show a reduced secondary electron (SE) emission after annealing, while As doped ZnO adjacent to the ZnO/GaAs interface demonstrates an enhanced SE emission and the enhanced luminescence associated with donor–acceptor pairs and exciton bound to acceptors.