| Zugriffsnummer |
46488 |
| Dokumenttyp |
Dissertation
|
| Peer Review |
unbekannt |
| Sprache |
Englisch
|
| Titel |
Systematic analysis of the impact of line-edgeroughness on the X-ray scattering pattern |
| Autor(in); Institution |
Fernández Herrero, Analía; 7.1, Radiometrie mit Synchrotronstrahlung, PTB-Berlin
|
| Quelle/Jahr |
(2021), VI, 138 S.
|
| Dissertationsvermerk |
Dissertation, Technische Universität Berlin, 2021 |
| DOI |
|
| URL |
|
| Verlag |
Berlin: Technische Universität
|
| Zusammenfassung |
Increasing miniaturization and complexity of nanostructures, e.g. in semiconductor industry, requires innovative metrology solutions with high throughput that canassess complex 3D structures and their imperfections in a non-destructive manner. Measurement techniques based on light-structure interaction are perfectly suitable for this purpose. Here, grazing incidence scattering techniques from the X-ray to the EUV region are investigated for the characterization of nanostructured surfaces emphasising the imprint of imperfections on the scattering pattern. Roughness is produced at different stages of the manufacturing process and affects the performance of the features. Numerous reports on the determination of dimensional parameters of nanostructures from scattering highlight the impact of roughness on the characterizationof the same. In lamellar gratings the randomly distributed variation of the edges of the line is known as line-edge roughness.To quantify line-edge roughness, semi-analytical theories derived for binary gratings have already been reported. However, their applicability for the characterization of roughness from real samples using grazing-incidence techniques has not been proved. In this thesis the effect of roughness on the diffracted intensities is systematically analysed by using a dedicated set of samples formed by periodic nanostructures with awell-defined roughness distribution. To extract the dimensional parameters of nanostructures from scattering patterns, a forward model is constructed and optimized. New procedures are developed for the complete numerical simulation of all aspects of the experiments. It is shown, that this is essential for the realistic derivation of parameter uncertainties. Moreover, the application limits of the Debye-Waller factor for the quantification of line-edge roughness in three-dimensional structures have been defined. The investigation of different types and distribution of line-edge roughness using grazing-incidence small angle X-ray scattering (GISAXS) and EUV small angle scattering reveals a strong correlation between the type of line roughness and the angular scattering distribution. The distinct diffuse scattering patterns open new paths for the unequivocal characterization of periodic nanostructures. Moreover, EUV scatterometry allows the investigation of smaller areas than GISAXS and is more robust to certain parameters, such asthe divergence of the photon beam. Finally, to improve the characterization of thecomplex structures of the next-generation nm-features using EUV and soft X-rays, the combination of fluorescence and scattering is proposed. In this regard, a new set-up is developed to further exploit this hybrid method. |
