David Nečas, Ivan Ohlídal, Daniel Franta

The reflectance of non-uniform thin films

Journal of Optics A: Pure and Applied Optics 11 (2009) 045202

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.

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DOI: 10.1088/1464-4258/11/4/045202

You can also contact one of the authors: yeti@physics.muni.cz, ohlidal@physics.muni.cz, franta@physics.muni.cz

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