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题名	金属薄膜光/电性质的尺寸效应及输运理论
作者	范平
学位类别	博士
答辩日期	2004
授予单位	中国科学院上海光学精密机械研究所
导师	邵建达
关键词	金属薄膜 光学特性 电学特性 尺寸效应 输运理论 最小连续膜厚
其他题名	Size effect of optical/electrical properties and transport theory of metallic films
中文摘要	随着纳米材料和纳米结构器件制备技术的发展，以及金属薄膜为组元构成的多层金属薄膜的研究进展，金属薄膜的输运理论和特性研究成果被广泛应用在金属多层膜的研究中。此外，对金属薄膜本身的研究也是非常有趣和重要的课题。论文利用离子束溅射等实验手段制备不同厚度的软X射线多层膜金属膜层的常用金属材料Mo、Co和Cu等薄膜，用Lambda-900测量制备的各种金属不同厚度薄膜的透射率、反射率，得到光学特性一膜厚关系曲线，研究了金属薄膜光学特性的尺寸效应。用四电极法测量制备的各种金属不同厚度薄膜的方块电阻，从而得到电导率一膜厚关系曲线。实验结果显示，Mo膜、Co膜和Cu膜的电学特性都有明显的尺寸效应。论文通过特性测量和结构分析研究了金属薄膜不同生长阶段物理性质的特征，提出了金属薄膜连续性的光学特性的特征判据和电学特性的特征判据，得到了不同制备条件和制备方法的金属薄膜最小连续膜厚。给出最小连续膜厚的光学特性特征判据和电学特性特征判据得到的最小连续膜厚基本相同。利用原子力显微镜（AFM）对给出的最小连续膜厚附近的不同厚度金属Mo膜、Co膜和Cu膜的表面形貌进行了观察。根据Lambda-900分光光度计对离子束溅射沉积不同厚度cu膜测定的反射率和透射率，论文运用Hadley方程，并考虑基片后表面的影响，对离子束溅射沉积的Cu膜光学常数进行了计算。结果表明，膜厚小于100nm的纳米Cu膜光学常数随膜厚变化明显；膜厚大于10onm后，Cu膜的光学常数趋于一定值。论文在Boltzmann方程的基础上，提出一个新的模型，建立了新的金属薄膜的电输运理论。在Fuchs-Sondheimer（F-S）理论提出的考虑表面散射的条件下，引入一个描述晶界散射影响的条件，提出同时考虑表面散射和晶界散射的金属薄膜的输运理论。从理论上对金属薄膜电导特性的尺寸效应进行了研究，并将建立的新的金属薄膜的电输运理论得到的电导率公式与论文得到的Co膜、Cu膜和Mo膜的实验结果比较，理论结果与实验结果符合得很好。弥补F-S理论在较薄厚度时与实验结果不相符的缺陷。讨论了应用金属薄膜连续性电学特性特征判据的最小连续膜厚理论计算公式。然后，重点讨论了金属薄膜的电阻率。建立的金属薄膜的半经典电输运理论解释了通常被认为是量子尺寸效应的典型例子的Pt薄膜和Bi薄膜的实验结果。因此，建立的金属薄膜电输运理论也适用于超薄金属薄膜。最后，讨论了金属薄膜的电阻率温度系数和热电势。本文得到的理论结果与实验结果在网状膜和连续膜时符合得很好。
英文摘要	Following advances in niicrofabrication of nano-material and nanostructures such as metallic multilayers, since a thin metallic film is basic units of metallic multiplayer, theoretical approaches to the transport in metallic films have been widdly applied to metallic multilayers. Besides, investigations in connection with the metallic films themselves have also been interesting and important. Mo, Co and Cu films of different thicknesses have been prepared by Ion-beam Sputtering. The reflectance and transmittance of Mo, Co and Cu films in the range of 310nm to 1300nm have been measured by Lambda-900 spectrophotometer. Relationships between reflectance, transmittance, absorptance and thickness of Mo, Co and Cu films in the wavelengthes selected have been discussed. The results showed that the optical properties of Mo, Co and Cu films have obvious size effect. The resistivities have been measured by a four-probe technique. Relationships between electric conductivity and thickness of Mo, Co and Cu films are given. The results show that the electrical properties of Mo, Co and Cu films have obvious size effect. Considering the results obtained from the properties measurement and analyses of the structure of metallic films, characteristics of physical properties of different growth stage of metallic films have been studied. A characteristic criterion of the optical properties and a characteristic criterion of the electrical properties of the growth of metallic films from discontinuous to continuous have been proposed. The minimal continuous thicknesses of metallic films that have been prepared by different deposition technique or different deposition conditions have been obtained. The minimal continuous thickness of a metallic film was obtained by a characteristic criterion of the optical properties and that by a characteristic criterion of the electrical properties are almost identical. Topography images of Mo, Co and Cu films near characteristic thickness were observed by using atomic force microscopy (AFM). Using Hadley equations, taking into account the correction due to the back surface of the substrate, the optical constants of ion beam sputtering deposited Cu films have been calculated. The results show that the values of the optical constants of Cu films along with thickness are changes evident if film thickness less than lOOnm and to a certainty value if film thickness bigger than lOOnm. We follow an approach using the Boltzmann equation in conjunction with boundary conditions suitable for describing surface scattering that were introduced by Fuchs and an additional new parameter to describe grain boundary scattering. A quasiclassical transport theory of metallic films has been developed. A general formula for the conductivity has been derived more rigorously in the presence of both the film surface scattering and grain boundary scattering. The in-plane electric conductivity of metallic films is obtained, and the theoretical results are shown to be in good agreement with experimental data. Whereas F-S theory fails to provide predictions to experimental studies for very thin films. Next we give the relationship between resistivity and thickness of metallic films and make a comparison with experiment. It is thought that the experimental data of Pt films and Bi films are examples of the quantum size effect (QSE). They are explained by our quasicalssical transport theory of metallic films. Therefore, our quasiclassical theory is applicable to the ultrathin metallic films. Finally, the temperature coefficient of resistivity and the thermoelectric power of metallic films have been discussed. These results are very well confirmed by experimental data for network films and continuous films.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15495]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	范平. 金属薄膜光/电性质的尺寸效应及输运理论[D]. 中国科学院上海光学精密机械研究所. 2004.

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