Elipsometrická charakterizace nehomogenních tenkých vrstev s komplikovanou neuniformitou v tloušťce: aplikace k nehomogenním polymerům-podobným tenkým vrstvám

Ellipsometric characterization of inhomogeneous thin films with complicated thickness non-uniformity: application to inhomogeneous polymer-like thin films

journal article in Web of Science

en

The method of variable angle spectroscopic ellipsometry usable for the complete optical characterization of inhomogeneous thin films exhibiting complicated thickness non-uniformity together with transition layers at their lower boundaries is presented in this paper. The inhomogeneity of these films is described by means of the multiple-beam interference model. The thickness non-uniformity is taken into account by averaging the elements of the Mueller matrix along the area of the light spot of the ellipsometer on the films. The local thicknesses are expressed using polynomials in the coordinates along the surfaces of the films. The efficiency of the method is illustrated by means of the optical characterization of a selected sample of the polymer-like thin film of SiOxCyHz, prepared by plasma enhanced chemical vapor deposition onto the silicon single crystal substrate. The Campi-Coriasso dispersion model is used to determine the spectral dependencies of the optical constants at the upper and lower boundaries of this film. The profiles of these optical constants are determined too. The thickness non-uniformity is described using a model with local thicknesses given by the polynomial with at most quadratic terms. In this way it is possible to determine the geometry of the upper boundary. The thickness and spectral dependencies of the optical constants of the transition layer are determined as well. Imaging spectroscopic reflectometry is utilized for confirming the results concerning the thickness non-uniformity obtained using ellipsometry. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Je prezentována metoda spektroskopické elipsometrie s proměnným úhlem použitelná pro úplnou optickou charakterizaci nehomogenních tenkých vrstev vykazujících komplikovanou neuniformitu v tloušťce spolu s přechodovými vrstvami na jejich spodních rozhraních. Nehomogenita těchto vrstev je popsána pomocí mnohapaprskového intereferenčního modelu. Neuniformita v tloušťce je vzata v úvahu zprůměrováním prvků Muellerovy matice podél plochy světelné stopy elipsometru na vrstvě. Lokální tloušťka je vyjádřena pomocí polynomů v souřadnicích podél plochy vrstev. Efektivnost metody je ilustrována pro případ vybraných vzorků polymerům podobných vrstev SiOxCyHz připravených technologií PECVD na podložce tvořené monokrystalem Si. K určení spektrálních závislostí optických konstant by užit Campi-Corriassův disperzní model na horních a spodních rozhraních vrstev. Jsou určeny rovněž profily těchto konstant. Neuniformita v tloušťce je popsána pomocí modelu s lokální tloušťkou vyjádřenou polynomy nejvýše druhého stupně. Takto je možné určit geometrii horního rozhraní. Je také určena tloušťka a spektrální závislosti optických konstant přechodových vrstev. K ověření výsledků týkajících se neuniformity v tloušťce obdržených pomocí elipsometrie byla užita zobrazovací spektroskopická reflektometrie.

The method of variable angle spectroscopic ellipsometry usable for the complete optical characterization of inhomogeneous thin films exhibiting complicated thickness non-uniformity together with transition layers at their lower boundaries is presented in this paper. The inhomogeneity of these films is described by means of the multiple-beam interference model. The thickness non-uniformity is taken into account by averaging the elements of the Mueller matrix along the area of the light spot of the ellipsometer on the films. The local thicknesses are expressed using polynomials in the coordinates along the surfaces of the films. The efficiency of the method is illustrated by means of the optical characterization of a selected sample of the polymer-like thin film of SiOxCyHz, prepared by plasma enhanced chemical vapor deposition onto the silicon single crystal substrate. The Campi-Coriasso dispersion model is used to determine the spectral dependencies of the optical constants at the upper and lower boundaries of this film. The profiles of these optical constants are determined too. The thickness non-uniformity is described using a model with local thicknesses given by the polynomial with at most quadratic terms. In this way it is possible to determine the geometry of the upper boundary. The thickness and spectral dependencies of the optical constants of the transition layer are determined as well. Imaging spectroscopic reflectometry is utilized for confirming the results concerning the thickness non-uniformity obtained using ellipsometry. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Elipsometrie, nehomogenní tenké vrstvy, neuniformita v tloušťce, nehomogenní polymerům–podobné tenké vrstvy.

Ellipsometry, inhomogeneous thin films, nonuniformity in thickness, thickness non-uniformity, inhomogeneous polymer-like thin films.

23.11.2020

Optical Society of America

WASHINGTON

1094-4087

28

24

36796–36811

16