Temperature-dependent electron microscopy study of Au thin films on Si (1 0 0) with and without a native oxide layer as barrier at the interface
Temperature-dependent electron microscopy study of Au thin films on Si (1 0 0) with and without a native oxide layer as barrier at the interface
复制标题
Si (1 0 0) 上金薄膜的温度依赖性电子显微镜研究，在界面处有或没有原生氧化层作为势垒
DOI：
10.1088/0022-3727/44/11/115301
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Germany
中科院分区：
文献类型：
--
作者：
A. Rath;J. K. Dash;R. R. Juluri;A. Rosenauer;P. V. S. I. O. Physics;Sachivalaya Marg;India Department of Physics;U. O. Bremen;Germany
用实时电子显微镜观察了沉积在Si（100）表面上的金纳米结构随退火温度的变化。在金薄膜沉积之前使用两种类型的与硅衬底的界面：（i）没有原生氧化物并且在超清洁重构Si表面上，以及（ii）具有原生氧化物覆盖的Si表面。在超高真空条件下，用分子束外延方法在重构Si（1 0 0）表面上沉积了约2 nm厚的Au薄膜，在相对较低的温度下（与在界面处具有自然氧化物的纳米金硅化物结构相比）形成了四重对称的纳米金硅化物结构。对于该体系，发现82%的纳米结构是纳米矩形状结构，平均长度为1.27 nm，纵横比为1.13，在1.700 °C下。在Si（100）表面上沉积的厚度约为5.0nm的Au薄膜，在较高温度（约850 °C）下观察到了矩形结构的形成.在这些高温下，硅化金的解吸遵循衬底的对称性。在界面处的原生氧化物被认为是像一个障碍的相互扩散现象。使用先进的电子显微镜方法进行结构表征。
Real-time electron microscopy observation on morphological changes in gold nanostructures deposited on Si (1 0 0) surfaces as a function of annealing temperatures has been reported. Two types of interfaces with silicon substrates were used prior to gold thin film deposition: (i) without native oxide and on ultra-clean reconstructed Si surfaces and (ii) with native oxide covered Si surfaces. For ≈2.0 nm thick Au films deposited on reconstructed Si (1 0 0) surfaces using the molecular beam epitaxy method under ultra-high vacuum conditions, aligned four-fold symmetric nanogold silicide structures formed at relatively lower temperatures (compared with the one with native oxide at the interface). For this system, 82% of the nanostructures were found to be nanorectangle-like structures with an average length of ≈27 nm and aspect ratio of 1.13 at ≈700 °C. For ≈5.0 nm thick Au films deposited on Si (1 0 0) surface with native oxide at the interface, the formation of a rectangular structure was observed at higher temperatures (≈850 °C). At these high temperatures, desorption of gold silicide followed the symmetry of the substrate. Native oxide at the interface was found to act like a barrier for the inter-diffusion phenomena. Structural characterization was carried out using advanced electron microscopy methods.