Determination of optical parameters of very thin (lambda/50) films

摘要

A straightforward approach for estimation of thickness (d), real ((epsilon)_(1)) and imaginary parts ((epsilon)_(2)) of the complex permittivity of very thin films from spectrophotometric measurements is presented. The uncertainties in (epsilon)_(1), (epsilon)_(2), and d due to methodical error and the uncertainties in the measured quantities are investigated. It is shown that the influence of these factors is considerable when (epsilon)_(1), (epsilon)_(2), and d are obtained simultaneously for each wavelength. The accuracy of (epsilon)_(1), (epsilon)_(2), and d is significantly increased if the value of d is evaluated first, its value is kept constant over the whole spectral region, and then (epsilon)_(1) and (epsilon)_(2) are calculated for each wavelength.