| Zugriffsnummer |
46901 |
| Dokumenttyp |
Dissertation
|
| Peer Review |
unbekannt |
| Sprache |
Englisch
|
| Titel |
Using grazing incidence Small-Angle X-Ray Scattering (GISAXS) for semiconductor nanometrology and defect quantification |
| Autor(in); Institution |
Pflüger, Mika; 7.2, Röntgenmesstechnik mit Synchrotronstrahlung, PTB-Berlin
|
| Quelle/Jahr |
(2020), 143 S.
|
| Dissertationsvermerk |
Dissertation, Humboldt-Universität Berlin, 2020 |
| DOI |
|
| Persistent Identifier |
|
| Verlag |
Berlin: Humboldt-Univ.
|
| Zusammenfassung |
Background.
The development of nanotechnology such as integrated circuits relies on an understanding of structure and function at the nanoscale, for which reliable and exact measurements are needed. Grazing-incidence small angle X-ray scattering (GISAXS) is a versatile method for the fast, contactless and destruction-free measurement of sizes and shapes of nanostructures on surfaces.
Aims.
A goal of this work is to investigate the possibility of precisely measuring the increasingly complex samples produced in science and industry using GISAXS. A second objective is to measure targets used in semiconductor quality control with a size of approx. 40 µm × 40 µm, whose signal is typically not accessible because an area of approx. 1 mm × 20 mm is illuminated at once.
Methods.
I take synchrotron-based GISAXS measurements and analyze them using reciprocal space construction, the distorted wave born approximation, and a solver for Maxwell’s equations based on finite elements.
Results. I find that the line shape of gratings with a period of 32 nm can be reconstructed from GISAXS measurements and the results deviate less than 2 nm from reference measurements; however, a careful Bayesian uncertainty analysis shows that key dimensional parameters do not agree within the uncertainties. For the measurement of small grating targets, I create a novel sample design where the target is rotated with respect to the surrounding structures and find that this efficiently suppresses parasitic scattering.
Conclusions.
I show that GISAXS measurements of complex nanostructures and small targets are possible, and I highlight that further development of GISAXS would benefit tremendously from efficient simulation methods which describe all relevant effects such as roughness and edge effects. Promising theoretical approaches exist, so that GISAXS has the potential to become an additional method in the toolkit of semiconductor quality control. |
