Reactive sputtering of ZnO:Al thin films from rotatable dual metallic targets
Reactive sputtering of ZnO:Al thin films from rotatable dual metallic targets
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DOI：
10.1016/j.apsusc.2012.07.080
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发表时间：
2012-10
影响因子：
6.7
通讯作者：
H. Zhu;J. Hüpkes;E. Bunte;Sumei Huang
中科院分区：
文献类型：
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作者：
H. Zhu;J. Hüpkes;E. Bunte;Sumei Huang
在等离子体发射监测（PEM）系统的控制下，采用反应溅射法制备了铝掺杂氧化锌（ZnO:Al）薄膜。系统地研究了放电功率、工作压力和工作点（或氧分压）等不同溅射条件对ZnO:Al薄膜的影响。结果表明，放电功率对沉积速率的影响很大。然而，不同的PEM强度导致不同的沉积速率，这与氧分压以及对氧化物（ZnO）和金属（锌）材料的溅射性能有关。此外，不同PEM强度下的氧分压对ZnO:Al薄膜的电学和光学性能以及形貌和蚀刻行为都有很大的影响。在过渡模式区获得了具有良好的电学和光学性能以及合适的表面结构的高速率ZnO:Al薄膜。实现了高达100nmm/min的高沉积速率和高达41cm2/Vs的高载流子迁移率，这证明了这种具有成本效益的溅射技术的巨大优势。采用一种新的两步刻蚀方法，可以进一步修饰高速率ZnO:Al薄膜的表面结构，并在硅薄膜太阳能电池中得到了良好的器件性能。
In this study, aluminum doped zinc oxide (ZnO:Al) films were prepared by reactively sputtering from rotatable dual metallic targets, which were controlled by a plasma emission monitoring (PEM) system. The influences of different sputtering conditions including different discharge powers, working pressures and working points (or oxygen partial pressure) on ZnO:Al films are investigated systematically. It is found that the deposition rate strongly relies on the discharge power. However, different PEM intensities lead to different deposition rates, which are related with oxygen partial pressure as well as the sputtering properties to oxide (ZnO) and metal (zinc) materials. In addition, the oxygen partial pressure at different PEM intensities strongly influences the electrical and optical properties as well as morphologies and etching behaviors of ZnO:Al films. High rate ZnO:Al films with good electrical and optical properties as well as proper surface structures are achieved at the transition mode region. High deposition rate of up to 100nmm/min and high carrier mobility of up to 41cm2/Vs are achieved, which demonstrates the great advantage for such a cost-efficient sputtering technique. The surface structure of high rate ZnO:Al films can be modified further by etching with a novel two-step etching method and good device performance has been achieved when they applied in silicon thin film solar cells.