@misc{10498/25743,
year = {2021},
month = {8},
url = {http://hdl.handle.net/10498/25743},
abstract = {Three means are investigated for further increasing the accuracy of the characterization of a thin film on a substrate, from the transmittance spectrum T(lambda) of the specimen, based on the envelope method. Firstly, it is demonstrated that the accuracy of characterization, of the average film thickness (d) over bar and the thickness non-uniformity Delta d increment over the illuminated area, increases, employing a simple dual transformation utilizing the product T(lambda)x(s)(lambda), where T-sm(lambda) is the smoothed spectrum of T(lambda) and x(s)(lambda) is the substrate absorbance. Secondly, an approach is proposed for selecting an interval of wavelengths, so that using envelope points only from this interval provides the most accurate characterization of (d) over bar and Delta d, as this approach is applicable no matter whether the substrate is transparent or non-transparent. Thirdly, the refractive index n(lambda) and the extinction coefficient k(lambda) are computed, employing curve fitting by polynomials of the optimized degree of 1/lambda, instead of by previously used either polynomial of the optimized degree of lambda or a two-term exponential of lambda. An algorithm is developed, applying these three means, and implemented, to characterize a-Si and As98Te2 thin films. Record high accuracy within 0.1% is achieved in the computation of (d) over bar and n(lambda) of these films.},
organization = {This work was supported by the European Regional Development Fund within the Operational Programme "Science and Education for Smart Growth 2014-2020" under the Project CoE "National Center of Mechatronics and Clean Technologies", contract No. BG05M2OP001-1.001-0008, L10S07 SynChaLab. The As98Te2 film on substrate specimens have been prepared with funding from the Russian Science Foundation grant 16-12-00038.},
publisher = {MDPI},
keywords = {increased characterization accuracy},
keywords = {thin film},
keywords = {envelope method},
keywords = {dielectric film},
keywords = {semiconductor film},
keywords = {transmittance spectrum},
title = {Further Increasing the Accuracy of Characterization of a Thin Dielectric or Semiconductor Film on a Substrate from Its Interference Transmittance Spectrum},
doi = {10.3390/ma14164681},
author = {Minkov, Dorian and Márquez Navarro, Emilio José and Angelov, George and Gavrilov, Gavril and Ruano, Susana and Saugar, Elias},
}