The reflectance of non-uniform thin films
The reflectance of non-uniform thin films
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非均匀薄膜的反射率
DOI：
10.1088/1464-4258/11/4/045202
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发表时间：
2009
影响因子：
--
通讯作者：
D. Franta
中科院分区：
文献类型：
--
作者：
D. Nečas;I. Ohlídal;D. Franta
在表示非均匀膜厚分布密度的基础上，推导了非均匀膜厚反射率的一般表达式。这种厚度分布密度的例子，对应于各种形状的厚度不均匀性，提出。此外，一个反射率公式推导出的一般公式展开成幂级数的均方根（rms）值的厚度分布的二阶近似。通过数值分析，它表明，对于较大的非均匀性，有必要考虑到他们的具体形状的光学表征，而对于小的非均匀性的具体形状是不重要的表征。理论结果被应用到一个选定的非均匀氮化碳膜的完整的光学特性。
A general formula for the reflectance of a thin film with non-uniform thickness is derived based on expressing its thickness distribution density. Examples of such thickness distribution densities, corresponding to various shapes of the thickness non-uniformity, are presented. In addition, a reflectance formula is derived as the second-order approximation of the general formula expanded into a power series in the root mean square (rms) value of the thickness distribution. By means of a numerical analysis, it is shown that for greater non-uniformities it is necessary to take into account their concrete shapes in the optical characterization, whereas for small non-uniformities the concrete shape is of no importance for the characterization. The theoretical results are applied to the complete optical characterization of a selected non-uniform carbon nitride film.