13 results on '"Thickness non-uniformity"'
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2. Optical Characterization of Thin Films by Means of Imaging Spectroscopic Reflectometry
- Author
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Ohlídal, Miloslav, Vodák, Jiří, Nečas, David, Ertl, Gerhard, Series Editor, Lüth, Hans, Series Editor, Car, Roberto, Series Editor, Rocca, Mario Agostino, Series Editor, FREUND, HANS-JOACHIM, Series Editor, Stenzel, Olaf, editor, and Ohlídal, Miloslav, editor
- Published
- 2018
- Full Text
- View/download PDF
3. Optimization Analysis of Large-Area Full-Field Thickness Measurement Interferometry in Thin Glass Plates
- Author
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Sung, Po-Chi, Wang, Wei-Chung, Li, Meng-Hsiu, Zimmerman, Kristin B, Series editor, Jin, Helena, editor, Yoshida, Sanichiro, editor, Lamberti, Luciano, editor, and Lin, Ming-Tzer, editor
- Published
- 2016
- Full Text
- View/download PDF
4. Investigation of the thickness non-uniformity of the very thin silicon-strip detectors.
- Author
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Liu, Qiang, Ye, Yanlin, Li, Zhihuan, Lin, Chengjian, Jia, Huiming, Ge, Yucheng, Li, Qite, Lou, Jianling, Yang, Xiaofei, Yang, Biao, Feng, Jun, Zang, Hongliang, Chen, Zhiqiang, Liu, Yang, Liu, Wei, Chen, Sidong, Yu, Hanzhou, Li, Jingjing, Zhang, Yun, and Yang, Feng
- Subjects
- *
SILICON detectors , *THICKNESS measurement , *PARTICLE range (Nuclear physics) , *CLUSTER theory (Nuclear physics) , *TELESCOPES - Abstract
The properties of some very thin ( ∼ 20 μ m) large-area Single-sided Silicon-Strip Detectors (SSSDs) were investigated by using the 12 C-particles elastically scattered from a Au target. In the detection system, each thin SSSD was installed in front of a thick (300 μ m or 500 μ m) Double-sided Silicon-Strip Detector (DSSD) to form a Δ E − E particle-telescope. The energy calibration of these detectors was realized by varying the beam energy and also by the irradiation from a three-component α -particle source. The thickness distribution each SSSD is precisely determined from the energy loss in the thin layer, which was independently measured by the corresponding DSSD. It is found that, for the SSSD with the nominal thicknesses of ∼ 20 μ m, the real thickness may vary by several μ m over the active area. The reason for this large non-uniformity still needs to be investigated. For the present application, this non-uniformity could be corrected according to the known pixel-thickness. This correction allows to restore a good particle identification (PID) performance for the entire large-area detector, the importance of which is demonstrated by an example of measuring the cluster-decays of the highly-excited resonant states in 16 O. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
5. TCAD simulation of organic field-effect transistors based on spray-coated small molecule organic semiconductor with an insulating polymer blend.
- Author
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Kaimakamis, Tryfon, Bucher, Matthias, Gioti, Maria, and Tassis, Dimitrios
- Subjects
- *
ORGANIC semiconductors , *ORGANIC field-effect transistors , *POLYMER blends , *SMALL molecules , *INTERFACIAL roughness , *DENSITY of states - Abstract
A commercial TCAD tool (Silvaco-Atlas) is used for the simulation of organic field-effect transistor (OFET) devices based on sprayed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-Pentacene) organic semiconductor and polystyrene (PS) insulating polymer blends (0.8:0.2 w/w). The simulation results are validated and improved after systematic comparison with experimental data. Shallow donor-like bulk and interface traps density of states (DOS) are taken into account for better convergence with the experimental data. Also, the necessity to include negative interface charge density was revealed. Furthermore, the constant low-field mobility model as well as the band-to-band tunneling model were selected, while their parameters were properly adjusted. Simulated electrical characteristics and experimental data demonstrate a very good agreement but necessitate further improvement. The important physical quantity of root-mean-square (RMS) roughness at the TIPS-Pentacene/PS interface is also included in the simulation considering various patterns. Different levels of RMS roughness at the active interface and different patterns are considered. Also, the TIPS-Pentacene thickness non-uniformity was examined, and the simulation results suggest that it is more significant when the TIPS-Pentacene thickness is thinner near the drain electrode side. Finally, the effects of non-uniformity on the device's overall electrical behavior are systematically investigated. [Display omitted] • TCAD simulation of the spray-coated TIPS-PEN:PS blend OFETs. • Inherent variability of the real devices demands different simulation parameters. • Need to include interface roughness and active channel thickness non-uniformity. • Improved fitting between simulated and experimental input and output I–V curves. • TIPS-PEN non-uniformity is more critical when it is thinner near the drain side. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Ellipsometric characterization of inhomogeneous thin films with complicated thickness non-uniformity: application to inhomogeneous polymer-like thin films
- Abstract
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.
- Published
- 2020
7. Ellipsometric characterization of inhomogeneous thin films with complicated thickness non-uniformity: application to inhomogeneous polymer-like thin films
- Abstract
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.
- Published
- 2020
8. Ellipsometric characterization of inhomogeneous thin films with complicated thickness non-uniformity: application to inhomogeneous polymer-like thin films
- Author
-
Ohlídal, Ivan, Vohánka, Jíří, Buršíková, Vilma, Šulc, Václav, Šustek, Štěpán, Ohlídal, Miloslav, Ohlídal, Ivan, Vohánka, Jíří, Buršíková, Vilma, Šulc, Václav, Šustek, Štěpán, and Ohlídal, Miloslav
- Abstract
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.
- Published
- 2020
9. On the effect of self-sustained periodic flows on film thickness non-uniformity during CVD.
- Author
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Kavousanakis, M., Cheimarios, N., Kokkoris, G., and Boudouvis, A.G.
- Subjects
- *
FILM flow , *STAGNATION point , *LAMINAR flow , *CHEMICAL vapor deposition , *TRANSPORT equation , *STAGNATION flow - Abstract
• Perform 3D transient simulations of Silicon Chemical Vapor Deposition. • We compute self-sustained periodic flows in a symmetric CVD reactor. • Arrhenius plots are constructed for self-sustained periodic flows. • In the transport limited regime the deposited films are highly non-uniform. Self-sustained periodic flows can be found in the laminar flow regime of a vertical, stagnation point CVD reactor. Here, we examine the effect of flow periodicity on the thickness non-uniformity of the deposited films. The case study is silicon (Si) deposition and we perform transient simulations by solving the continuity, momentum, energy and species transport equations in order to compute the film thickness and uniformity on a single wafer for different operating conditions. The Arrhenius plot of the process is constructed to identify the different regimes of deposition. Our results reveal that CVD process under self-sustained periodic flows produces highly non-uniform films which are dysfunctional for practical applications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Characterization of non-uniform diamond-like carbon films by spectroscopic ellipsometry
- Author
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Ohlídal, Ivan, Nečas, David, Franta, Daniel, and Buršíková, Vilma
- Subjects
- *
CARBON , *THIN films , *OPTICAL properties , *SPECTRUM analysis , *ELLIPSOMETRY , *OPTICAL constants , *MATHEMATICAL models - Abstract
Abstract: Optical characterization of diamond-like carbon (DLC) films non-uniform in thickness is performed using spectroscopic phase-modulated ellipsometry. This characterization is based on new formulas for the associated ellipsometric parameters of thin films exhibiting a wedge-shaped thickness non-uniformity. These formulas express the associated ellipsometric parameters by means of the density of distribution of local film thickness. The spectral dependences of the optical constants of these non-uniform DLC films are expressed using the dispersion model based on parametrization of density of electronic states. It is shown that this model of the thickness non-uniformity provides a relatively good agreement between the experimental and theoretical data, indicating that the results of the optical characterization of the non-uniform DLC films are close to the correct results. Moreover, it is shown that the model of uniform thin films is unsuitable for the optical characterization of the non-uniform DLC films studied. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
11. Determining shape of thickness non-uniformity using variable-angle spectroscopic ellipsometry.
- Author
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Vohánka, Jiří, Šustek, Štěpán, Buršíková, Vilma, Šklíbová, Veronika, Šulc, Václav, Homola, Vojtěch, Franta, Daniel, Čermák, Martin, Ohlídal, Miloslav, and Ohlídal, Ivan
- Subjects
- *
SPECTROSCOPIC imaging , *MUELLER calculus , *THIN films , *ELLIPSOMETRY , *FILM studies , *REFLECTOMETRY - Abstract
• Thickness non-uniform films are studied by variable-angle spectroscopic ellipsometry. • The shapes of non-uniformity are modeled using a polynomial. • A correct shapes of non-uniformity can be obtained using ellipsometry. • The maps of local thicknesses also obtained using imaging spectroscopic reflectometry. The effects of thickness non-uniformity on measured optical quantities must be often considered in the optical characterization. The effects of thickness non-uniformity can be taken into account by averaging the Mueller matrices over the distribution of local thicknesses within the measured area. The distribution of local thicknesses can be assumed in a certain form (e.g. the uniform distribution), or it can be derived on the basis of a model assuming a certain shape of thickness non-uniformity. The latter approach is especially useful for the variable-angle spectroscopic ellipsometry since it can take into account dependence on the incidence angle due to the changes in the size of the light spot. This paper presents results of the optical characterization of three polymer-like thin films highly non-uniform in thickness using variable-angle spectroscopic ellipsometry. The shapes of the thickness non-uniform films are determined on the basis of a model assuming local thicknesses given by quadratic polynomials in coordinates along the surfaces of the films. The studied areas on the films were also measured by the imaging spectroscopic reflectometry, which provides a more direct method to determine local thicknesses. The results achieved using the imaging spectroscopic reflectometry and variable-angle spectroscopic ellipsometry were then compared. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
12. Optimizing parallel section length for small tensile specimen with fabrication non-uniformity in thickness.
- Author
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Liu, Haiting, Chen, Ran, Wen, Mao, Zhang, Lei, and Shen, Yao
- Subjects
- *
NUCLEAR industry , *TENSILE tests , *RADIOACTIVE substances , *MECHANICAL properties of condensed matter - Abstract
• Slight thickness non-uniformity can significantly influence the results of thinner small specimens. • The difference between non-uniform and uniform small specimens can be diminished by shortening the parallel section length. • There exists an optimal design that minimizes the difference between non-uniform small specimen and standard specimen. Miniature tensile test has been widely used to evaluate the tensile properties of the materials in nuclear industry and other fields. However, the thinner (e.g. 0.2 mm) the specimen becomes, the larger the scatter of the tensile results is. The scatter is closely related to thickness non-uniformity, as our finite element simulations demonstrated that slight thickness non-uniformity leads to significant deviation of the tensile results from the uniform specimen. The deviation was found to decrease with decreasing parallel section length (PSL) in small specimens. On the contrary, the deviation of the shortened uniform specimens from the standard specimen increases with decreasing PSL. The comprehensive result of these two opposite trends leads to a non-monotonic variation of the deviation of the small non-uniform specimens from the standard specimen. A minimal deviation can thus be found, which corresponds to an optimal design of the PSL. This optimal length is shorter than that of the small specimen which is scaled down directly from the standard one and has the same thickness and width as the optimal one. With this optimal design, the small specimens can be further reduced in volume and are easy in handling because of their higher stiffness. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
13. Defect Detection and Thickness Mapping of Passivation Layers on Integrated Circuits Using Energy Dispersive X-Ray Analysis and Image Processing Techniques
- Author
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Sartore, Richard G.
- Subjects
Scanning Electron Microscope (SEM) ,Image processing ,thickness mapping ,Hole defect detection ,thickness non-uniformity ,passivation layer ,silicon dioxide layer ,Energy Dispersive X-ray Analysis (EDXA) ,Biology - Abstract
The relative thickness of passivation layers has been mapped for integrated circuits by utilizing the penetration voltage method, in conjunction with energy dispersive x-ray analysis (EDXA) and a scanning electron microscope (SEM), to detect defects and map film thickness. The thickness mapping technique was evaluated for area coverage and correlated to size of defective areas. The purpose of this study was to determine optimal operational conditions for fast and accurate defect detection on an integrated circuit for failure analysis and non-destructive process evaluation. Image processing was required to enhance the acquired map and to obtain a calibrated image for relative comparison of thickness non-uniformity. Once the defect is detected, linescan and spot measurements can be used to obtain more accurate characterization of the defect areas. Considerable improvement in the detection and characterization of thickness and hole defects in the passivation layers on integrated circuit devices can be obtained with the use of this method.
- Published
- 1988
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