RT journal article
T1 Further Increasing the Accuracy of Characterization of a Thin Dielectric or Semiconductor Film on a Substrate from Its Interference Transmittance Spectrum
A1 Minkov, Dorian
A1 Márquez Navarro, Emilio José
A1 Angelov, George
A1 Gavrilov, Gavril
A1 Ruano, Susana
A1 Saugar, Elias
A2 Física de la Materia Condensada
K1 increased characterization accuracy
K1 thin film
K1 envelope method
K1 dielectric film
K1 semiconductor film
K1 transmittance spectrum
AB 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.
PB MDPI
SN 1996-1944
YR 2021
FD 2021-08
LK http://hdl.handle.net/10498/25743
UL http://hdl.handle.net/10498/25743
LA eng
NO 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.
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026