New Method for the Complete Optical Analysis of Thin Films Nonuniform in Optical Parameters

Abstract

In this paper, a new optical method for characterizing thin films exhibiting area nonuniformity in optical parameters is described. This method is based on interpreting the spectral dependences of the reflectance measured using the special experimental arrangement described in detail. Using this method, the distribution of both the optical parameters, i.e. the local thickness and local refractive index, describing the thin film studied can be determined along a large area of the substrate. It is shown that the method presented can be employed for determining strong nonuniformities in the optical parameters of the films studied. The method is illustrated through the optical analysis of strongly nonuniform thin films formed by a mixture of CNx and SiOy deposited onto silicon single-crystal substrates.